The Arithmetic Snake

** TODAY'S PUZZLE **
We love snake puzzles and this is a cracker! It's by Scruffamudda and involves a tiny bit of modulo arithmetic (!). You can try "No '0' In Adder" at the link below:
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Rules:
Normal sudoku rules apply. Additionally the solver must find a single snake of orthogonally connected digits beginning at the given 1 which does not touch itself (even diagonally), does not touch any white dots but must visit each 3x3 box in the grid. Each digit on the snake is the sum of the previous two digits modulo 10 (eg 5+7 = 2). NB The second snake digit after the given 1 can be any digit. Grey digits are not on the snake but show the number of snake cells in the surrounding (up to) eight cells. Cells separated by a white dot must contain consecutive digits. Not all possible dots are given.
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[@scruffamudda6306]

Thanks Simon! I thoroughly enjoyed watching your solve and very glad you enjoyed it. Side note: The sequence beginning with 1,3 also works without an "O" but is ruled out by box 1 logic.

[@elvagabundo4607]

That was a terrific puzzle Scruffamudda, i really enjoyed the Fibonacciean?? sequencing. I have one question, at the end of Simon's solve, he didn't use the white dot in row 9, and I didn't either. Did it come into play at some other point in the solve? Looking forward to your next featured puzzle on the channel. :)

[@RichSmith77]

@@elvagabundo4607 Simon uses the white dot in row 9 at 43:15 to enter the last two digits in box 7, the 2 and 9. There's another solution possible without the white dot. (The 2,9 switched in box 7, the 7,8 switched in box 2, and a few other digits switched around in rows 8 and 9, columns 5 and 6)

[@elvagabundo4607]

@@RichSmith77 Doh! sumtimes i is soooooooo stupid! Thanks for showing me the light Richard :)

[@msolec2000]

Which is in fact the same sequence, just starting at a different point.

[@stephenbeck7222]

Amazed that Simon both felt the need to keep his pencil mark sequence after getting one full cycle of true digits filled in, AND that he didn’t screw up his sudoku with those marks!

[@jamestut5220]

Moreover, he completely forgot the rule that the next cell is the sum of the previous two mod 10. I am surprised he just referred to the sequence instead

[@MagicWazam]

@@jamestut5220 trading storage space for processing power, common tactic in programming

[@Adrian_Grey]

Simon: does long division in his head Also Simon: refuses to do very simple addition

[@TheMeanderingduck6]

"Why is there a 7?" when Simon just stumbles randomly into things is the best

[@goldenknight578]

I was waiting for that moment. Simon's becoming a little bit predictable.🤣

[@pouletbelette]

@@goldenknight578 Very much indeed. But only to entertain us even more! 🤣

[@Anthony-yn3fg]

it was so funny , i didn't even notice he left it !

[@MrRomanGuy]

I laughed hysterically when he finally found the errant 7.

[@lexihopes]

@@Anthony-yn3fg I was half paying attention while making food and when i focused fully I was like wait why's there a 7? I figured it had to do with when he tried the 3 but I wasn't 100% that he didn't figure something out back then. I love that it was in the right place though.

[@RiviRrapper]

It made me so delighted when Simon quizzically found the "7" in the right place

[@jonasf94114]

Fun that Simon insists on keeping the sequence of digits as pencil marks, thus interfering with his solve even though that exact sequence is fully written on the snake at 33:33

[@pema22]

I did shout at him for that ;)

[@ethanwinters1519]

43:57 Actually from a puzzle constructing standpoint I think it's a bit cooler, since 1,3 also works as a start because you get 1, 3, 4, 7, 1, 8, 9, 7, 6, 3, 9, 2, 1, 3 and on it repeats without a 0. But it looks like the start of the puzzle was careful constructed specifically to exclude this possibility, which I think is pretty cool. Good work Scruffamudda!

[@reubenmckay]

I noticed this as well. 1,3 and 1,8 are the only two starting numbers to the sequence where the snake can grow long enough to reach all the boxes before hitting 0.

[@dkamm65]

Interestingly, that's the same sequence, it just begins at a different point.

[@pengchengwu447]

@@dkamm65 Not same sequence, but they end up in the same loop...

[@dkamm65]

@@pengchengwu447 It is the same sequence. It's the same 12 digits in the same order, creating a loop. The only difference is where in the loop you begin, 1, 8, 9, or 1, 3, 4.

[@geodave227]

yes!

[@jonnybolton4659]

18 isn't the only beginning that results in an infinite sequence, so does 13. I love how the given 1 and the grey cells were constructed to cancel out one of those options, so clever!

[@fakjbf3129]

Actually they are the same sequence starting at different points in the cycle.

[@daglisar589]

I can't stop watching this videos. I don't like sudoku but there is something in Simon's voice that makes me relax. On top of that my english might improve a little since i have no way to practice a second language

[@SmartHobbies]

A picture is worth a 1,000 words when it comes to some of these rule sets. Thank you Simon for showing us how to do it.

[@HunterJE]

Regarding the updates to the apps - been gradually making my way through the added puzzles in the thermo app lately (both the newest and others that have been added since last I worked my way through it) and this should come as no surprise but the puzzles credited to Sam Cappleman-Lynes are universally so pleasing and gorgeously crafted.

[@th.nd.r]

Wonderful setting Scruffamudda, it’s a wonderful concept that is equal parts complex and intuitive, quite elegant, aptly titled. Great solve Simon! PS once again, there is not one, but TWO 3s in corners, NEITHER of which got songs!!

[@emilywilliams3237]

I love how much you love snake puzzles, Simon. It really comes through in your solves. And I have learned to understand snake puzzles and how to approach them through watching these videos. Thanks for that. Today's vocabulary gems include "delectation" and "replete." So much to love on CTC! On the solve, I was at first amused that you felt you had to keep the sequence of digits in sight, but then, when the snake made its way around toward the bottom of box six, I saw that having them available enabled you to look ahead, rather than calculating them afresh each time you wanted to know the next one. So that turned out to be a pretty smart move. Not that I doubted you, of course ... 😊

[@nezarnassif2967]

Snake puzzles are my one of my favorite puzzles, and I love when youtube suggests one from the past that I haven't solved yet.

[@inspiringsand123]

Rules: 02:45 Let's Get Cracking: 06:30 Simon's time: 37m12s Puzzle Solved: 43:42 What about this video's Top Tier Simarkisms?! Phistomefel: 1x (02:22) And how about this video's Simarkisms?! Snake: 128x (00:17, 02:50, 03:01, 03:05, 03:05, 03:10, 03:24, 03:35, 03:51, 05:00, 05:15, 05:25, 05:29, 05:33, 05:42, 05:45, 06:39, 06:41, 06:42, 06:44, 06:47, 07:07, 07:09, 07:14, 07:33, 07:36, 08:10, 08:36, 08:49, 08:51, 08:58, 09:03, 09:05, 09:25, 09:33, 09:59, 10:29, 10:33, 10:36, 10:44, 10:47, 10:52, 10:55, 12:13, 13:40, 13:42, 14:03, 14:03, 14:09, 14:13, 14:48, 15:13, 15:17, 15:31, 17:42, 21:12, 22:56, 24:29, 25:23, 25:41, 25:45, 26:12, 26:18, 26:18, 26:20, 26:22, 26:24, 26:33, 27:03, 27:03, 27:18, 27:38, 27:53, 29:07, 29:12, 29:16, 29:24, 29:30, 29:32, 29:34, 31:02, 31:08, 31:11, 31:15, 31:26, 31:33, 31:44, 32:00, 32:04, 32:08, 32:22, 32:25, 32:40, 32:50, 33:29, 34:12, 34:32, 36:52, 37:16, 37:20, 37:25, 37:43, 37:46, 37:58, 37:58, 38:11, 38:16, 39:01, 39:07, 39:23, 39:23, 39:59, 40:01, 40:01, 40:05, 40:25, 40:46, 40:49, 40:53, 41:46, 41:46, 41:48, 42:02, 42:38, 44:34, 44:36, 44:52, 44:54) Ah: 22x (12:10, 13:55, 16:42, 16:57, 21:03, 22:15, 23:23, 24:23, 24:26, 24:39, 25:59, 26:30, 27:30, 33:08, 33:18, 33:59, 34:40, 35:07, 36:41, 37:12, 40:39, 40:57) By Sudoku: 13x (08:43, 09:08, 12:18, 22:00, 24:45, 30:00, 30:52, 34:45, 38:34, 38:36, 38:41, 42:11) Touch Itself: 12x (02:56, 03:10, 03:16, 03:24, 09:53, 25:23, 29:32, 32:08, 32:44, 37:43, 38:00, 41:08) Beautiful: 9x (01:28, 22:15, 30:19, 31:55, 37:12, 38:21, 41:41, 43:52, 44:16) In Fact: 8x (04:23, 06:39, 06:52, 08:55, 28:12, 28:52, 32:37, 32:40) Lovely: 6x (14:52, 22:15, 37:12, 44:40, 44:40, 44:40) Hang On: 6x (16:57, 18:36, 19:26, 24:29, 24:39, 28:39) Break the Puzzle: 5x (29:15, 30:14, 30:23, 30:25, 44:36) Pencil Mark/mark: 4x (23:03, 23:16, 33:42, 35:59) Sorry: 2x (25:53, 39:43) Brilliant: 2x (01:06, 01:50) Whoopsie: 2x (03:05, 06:07) Good Grief: 1x (24:20) What on Earth: 1x (37:35) Naked Single: 1x (24:18) The Answer is: 1x (30:52) Nonsense: 1x (15:27) Naughty: 1x (03:10) I Have no Clue: 1x (10:13) Stuck: 1x (35:32) Extraordinary: 1x (02:16) Elegant: 1x (38:38) Barbaric: 1x (15:57) Doesn't get a Song: 1x (32:14) Obviously: 1x (11:14) Cake!: 1x (01:07) Uniqueness: 1x (25:16) Most popular number(>9), digit and colour this video: Ten (11 mentions) Seven (81 mentions) Green (15 mentions) Antithesis Battles: White (9) - Black (0) Row (3) - Column (2) FAQ: Q1: You missed something! A1: That could very well be the case! Human speech can be hard to understand for computers like me! Point out the ones that I missed and maybe I'll learn! Q2: Can you do this for another channel? A2: I've been thinking about that and wrote some code to make that possible. Let me know which channel you think would be a good fit!

[@steve470]

Only one "naughty" in a snake puzzle? So disappointing.

[@Xiuhtec]

Somehow this puzzle just clicked with me very easily. Normally I take over an hour even when the video is half that or less, but I did this one in 17 minutes. The logic just flowed very smoothly after realizing only one sequence didn't fall into a zero trap. Beautiful setting!

[@steveunderwood3683]

I usually struggle with these snake like puzzles, but that one was very straightforward. It looks hard at first, but once you realise that only one sequence can work, it goes quite smoothly. I did the last part really quickly when I realised 189 was in the last row of box 4, and that is a part of the sequence.

[@Rubrickety]

I'm amused that, having penciled in the sequence, Simon felt the need to consult it to determine facts such as 2+1=3.

[@TheAcer4666]

Those are just the kind of knowledge bombs they share on Cracking the Cryptic

[@HarleyMaebry]

Simon, worrying about overwriting your pencil mark sequence after you already have one full iteration of the sequence placed on the snake is a bit silly. Just look at the snake! Or do math to find the next number in the sequence, but I can understand not wanting to constantly redo the maths. Having said that, I’ve actually been trying to do these puzzles the past couple days and getting nowhere, so definitely a tip of the hat for making a snake that doesn’t touch itself!

[@HunterJE]

Yeah felt a little silly to me too rewriting once the whole cycle was already on the snake itself

[@JackFate76]

Just look at YOUR snake. It gives you all the answers.

[@masheroz]

The less thinking you have to do, the less chance of mucking up.

[@lexihopes]

Yeah even with the repeats you can just mark the cell that's the end in some way.

[@Torauth]

Loved solving this! Felt like a badass smashing the digits in for the snake :D Great puzzle!

[@RichSmith77]

At 33:10, if only the 12 digit snake sequence appeared somewhere in the grid where it wouldn't need to be overwritten 😂.

[@Ratzfaz]

and if it were also marked purple, then you could still see it well ;-)

[@SpeedyBozar]

Maybe the most impressive creation I have seen on this channel. I almost cannot believe this actually turned out to be a legitimate way of designing sudoku. And not just that. Even the rest of it all is so elegant and smooth. Yet somehow it felt so natural to me that I solved it in a relatively short time.

[@Gonzalo_Garcia_]

38:36 for me. What a wonderful puzzle!! It took me a while to be sure about the sequence of digits, but once you get that it’s not too tough to finish it. Again, awesome puzzle.

[@mordirit8727]

I might have missed some good stuff before, but this was by far the most approachable snake puzzle I've ever seen here, first time I managed to finish a snake puzzle without any help with the break-in, absolutely enjoyable puzzle!

[@piarittersporn]

I had to watch Simon for about a quarter of an hour to fully understand the rule... so as not to have to bother the translator. After that I was able to assemble the snake without any problems and solve the puzzle in 40 minutes. That was an amazing adventure. After that I enjoyed Simon's solution.

[@davidh.4944]

2:18:47 for me, with one small bit of video help. I got stuck at determining 3 or 8 for the second digit, and watched to see how that got resolved. I feel stupid for missing it, and certainly could've worked it out myself if I'd thought about it just a bit more. Other than that, I did it all on my own.

[@HunterJE]

9:33 If you look at the two possible arrangements to satisfy the 2 clue closely you can see that not only do both contain r1c3 as Simon shaded, they also both contain r1c2...

[@HunterJE]

(Would have made placing the 9 in the third cell of the snake much quicker to have noticed and marked this earlier)

[@b-you-tube]

Thanks for sharing this wonderful puzzle, Simon; and thank you Scruffamudda for making it. I solved it in 100 minutes

[@HunterJE]

31:00 Even without the 5 logic this arrangement breaks the puzzle by the rules for the snake - from this position there's no way for the snake to visit both the NE and SW boxes from here without touching itself, since it would have to reach one then backtrack to get to the other but the remaining available routes to each both have 2-cell-wide bottlenecks that make it impossible to get in and out legally...

[@Sam_weiqi]

This was the logic I used. Made things easier :-)

[@scruffamudda6306]

This was my approach too. I hadn’t considered the “5” logic to be honest

[@charliemurphy1269]

thats how i did it too!

[@rnisthal]

Phew I used this too

[@Thurhame]

Same here

[@filmemitelfe6972]

I solved this and came back to watch Simon do it so much more elegantly. I am proud of myself that I did it but a little frustrated because I missed some logic and was just lucky that it did not mess up my solve

[@TMThesaurus]

I love puzzles like this. Wonderful solve, Simon

[@lucky1time811]

This was one of my favorite puzzles! Had to think several steps ahead.

[@LittleBallOfPurr]

We both used 45 minutes! Though, I also used 2 hours. My first time playing anything more advanced that Killer Sudoku, so I'm happy enough to have got there, even if I do need a brain massage now. A really beautiful puzzle, thanks :)

[@ericpraline1302]

Interesting mix of maths and sudoku. Assumed at the start that the modulo 10 would be useless but soon hit a wall and was something of a revelation to find that the options for the chain were so limited.

[@G4M1L]

The cyclic sequence has some nice properties which among other things allowed me to tackle the snake from both ends. It is alternating between 1469 and 2378, also every fourth digit is either identical or differs by 5, which nicely fits in with neither 0 nor 5 being on it.

[@Matthew-eu4ps]

I actually found a technique which Simon didn't see, even though I was still slower. Right near the beginning I could fill out the 1897 at the end of the snake, and finish it from both ends.

[@mareksroka5629]

This is what I did too. Not right at the begining, but I ended up finding the ending, and use that to speed up my solve

[@nemuchan]

Absolutely adore when you have to build something in the grid ( snake, régions, etc.)

[@SolreLami196]

Figuring out the snake goes up in column 6 in the most Simon way possible. Quicker to realize that it’s the only way for the snake to get to box 3 (otherwise it touches itself going up and back down)

[@RichSmith77]

If the snake ended in box 3 then it wouldn't need to come back down. You also need to realise the snake would be forced to touch itself when doubling back in the lower part of the grid, having visited box 7.

[@AnnieBananie712]

Sometimes I accidentally pause the video and I just think that he’s been thinking about something for a really long time

[@aziidio]

I enjoyed this one a lot! My time was 68:24 -- getting closer to Simon's time every day ;)

[@sanabas1]

Fantastic puzzle, love the different thinking required. I ended up constructing the last part of the snake in reverse, from @39:00 in the video, working backwards from the 9 the next 6 cells of the snake are forced.

[@jomo87]

Same, sort of! I thought I was sooooo clever by working out the parity on the snake (since there are 12 digits in the 189763921347 loop, and given the movement rules for the snake, it means odd and even-numbered snake digits make a checkerboard-like pattern in the grid) - using that, the three pink cells in box 4 could only be 189, right to left. Then made a simple pencil-marking error in box 5's grey digit and screwed myself :p

[@Tfin]

I solved this at a pretty steady pace, and much faster than I expected based on the video length. I wish I'd remembered to restart the timer when I came back to it after pausing to get a drink right at the start.

[@KombatGod]

Great puzzle! I didn't even notice the fact that the sequence can't have a 5 on it, I solved the middle box using different logic: if the snake went down to box 8 then it'd have to either get back up to box 5 immediately and move to box 4, but that would block the path at the bottom preventing it from reaching boxes 3, 6, and 9, or it could move to the right-hand boxes first but because the "access" to box 3 is only two cells wide it couldn't go back and the snake would end there without reaching boxes 4 and 7. So that told me that the snake had to go in box 3 first and then move down.

[@user-kt9vr1wj6y]

well-designed puzzle,wonderful path!

[@Sam_weiqi]

Yay for snake puzzles!!

[@logiciananimal]

Gorgeous idea.

[@justsignmeup911]

I missed the "doesn't touch dots" rule and spent 15 minutes proving the snake doesn't go down at the start....

[@longwaytotipperary]

Words to the wise - don't pollute your snakes. 😄

[@klausku3285]

Wonderful puzzle. Took me 1,5 hours, but I enjoyed every minute. Thanks.

[@57thorns]

Took me just over 27 minutes and then I thought the snake was ambiguous, before I realised it had to visit all boxes. This would have given me a digit that would have helped the last unravelling of the sudoku part. Once I got my head around it I really enjoyed solving it.

[@57thorns]

At least I know for a fact that adding two digits modulo 10 in my head is one are where I have an advantage compared to Simon. I had no need to write down the sequence.

[@dylanlenn7836]

kept screaming for Simon to do the math instead of looking at the sequence after a while

[@davidh.4944]

Unnecessarily doing the same calculations again and again is tedious and prone to error. The bigger facepalm is why he insisted on writing the whole sequence out again when it was already available on the snake itself.

[@longwaytotipperary]

Totally delightful puzzle! ☺

[@ikog1]

24:25 If (according to the rules): 1.a solver MUST find a single snake of orthogonally connected digits (which implies that all the cells of the snake must be found); 2.Consecutive snake cells 8 and 9 result in the value of the next cell to be 6, by the modulo rule; Then, 1st row 4th column could not have been a 6 because there would be no way of knowing which one is the snake 6 and which one is a normal 6 - resulting in failure of finding all the snake cells.

[@andersruud1266]

You could also tell that the snake had to go up from the 3 in the middle box, because the snake could not visit box three without touching itself if you go down(going up in colloum eight, going down colloum nine: rule break)

[@mareksroka5629]

Came here to say this :)

[@beatlesunderwoood]

It could have conceivably ended in box 3 after visiting the other boxes.

[@mareksroka5629]

@@beatlesunderwoood I don't think it could. I need to check again the situation in Simon's solve, but in mine, the snake didn't have enough room go to box 7, then loop back to box 3 without touching itself.

[@jackming-hung8064]

33:15 he got the digets in the purple snake.

[@Mereczowszczyzna]

Your solve was so much smoother than mine ! I'm amazed as always ^^ Loved solving this puzzle. But I had to keep fighting with my brain though to stop assuming where the snake couldn't go (which would have caused many mistakes). "Oh it can't go there [...] WAIT actually it could!"

[@Anthony-yn3fg]

these snake ones are my favourite 🐍🐍

[@mskleftwich]

First video my husband wanted to watch with me 😄 A fun one for sure!

[@Coyotek4]

38:20 ... I'm a sucker for 'snake' Sudokus! Nice puzzle!

[@mareksroka5629]

"There is 8 here or a 8 here, both are plausible" (Simon at 33:00). It was funny because they both are ^^

[@mikepictor]

29 minutes, flowed pretty straightforward, but I confess I let Simon figure out the chain (IE the one possible sequence that worked) and I lifted that from the video

[@sebbe9843]

I loved this!

[@marsdenrhodri]

42:06 “Is it safe to get rid of this?” Yes, it is. It really is 😀

[@stevendeherrera2240]

3:09...I never laughed so hard at sudoku...I know, I know, I'm a child but still

[@srwapo]

33:34, but I had to see parts of the video through the first four boxes or so to learn how to think about the solve. I would have never thought to figure out which digits go into the snake before drawing it!

[@zoicon5]

Only 42 minutes for me this time, for me is actually pretty good.

[@mareksroka5629]

55:52 for me, because I wasted 20 minutes failing to see that the 2 in r3c2 didn't mean the snake had to go east right away. Very enjoyable solve once I found my mistake.

[@kamnale1317]

i also noticed at the beginning, that there could not be a 5 on the snake, but during my solve i never used that info

[@TheShadowplayer]

The puzzle/solve reminded me of minesweeper somehow with the grey boxes and having the number of surrounding snakes 8)

[@Klimentovici]

Worth noting that the Adder is also a snake of "addings" (each cell is determined by adding the previous two)

[@bibliopolist]

Thanks for the info about the apps. I have the killer app and will try the rest of the puzzles (and delete this whole thing afterwards, I hate the interface _so_ much).

[@ulrichclamence9044]

I was wondering wether 5 not being on the snake is a coincidence. So the question is: Given some positive integer n, suppose there's a sequence starting with 1 such that every number is the sum of the previous two modulo 2n and the sequence shall not contain a 0. Can n be on the sequence? The answer: Yes, but only the sequence 1->n->n+1->1->... is possible. As soon as one can rule out this option (which is trivial in the given Soduko as 1 can't be in the fourth position), it follows that n can't be part of the sequence. It's pretty simple if you you think about it and doesn't really help with solving the puzzle, but I thought I probably won't be the only one asking myself this question (in the middle of the night on a Saturday 😅).

[@anaphysik]

Perhaps an editable textbox would be a nice option for Sven to add to the app, to allow the jotting down of information. I personally keep a pad of scrap paper handy while doing puzzles, but I understand why you wouldn't want to do that for videos.

[@msolec2000]

There's a nice modulo 5 repeating of the snake. The columns below are single digit mod 5 1897... 6392... 1347...

[@lexihopes]

27:30 Both possibilities for the white dot actually forced the 8 in box 1. 789 for the obvious sudoku reason. 45 made the grey cell a 6 and forced the 8 that way. The way Simon did it made more progress though.

Interesting to note that the position of 1 and th 2 forbids the sequence to start 1347..That sequence would work in another layout. 134718976392 etc.

[@NinjaOnANinja]

17:40 Watch your mouth. There is nothing wrong with a snubby snake. I got your back, you know who you are.

[@gi0nbecell]

There are even two 3s in corners. Those poor threes were doubly left out - not only did neither get a song, nor were they allowed on the snake. I feel bad for those little digits! Simon, how about a shoutout to those threes in tomorrow’s video?

[@longwaytotipperary]

❤ for the snakeless 3's in the corner without a song.

[@floccinaucci]

32 minutes, but did do bifurcation a few times and screwed up my pencil marking in box 7s kropke domino.

[@lukostello]

you should use OBS to do stuff like write the 12 digit long sequence above your head for reference.Or maybe you could even get a 2nd camera to show what you're writing down on a notepad

[@solfeinberg437]

I found the instruction that the snake must be orthogonally connected and cannot touch itself even diagonally. Wouldn't a cell that went up and then to the right create a situation where the first cell touched the third diagonally? I feel like it should say cannot touch itself even diagonally, except for the above immediately proximate case.

[@GrAnAdMaN3]

there are only 2 mod 10 sequences without a 0 and only 1 contains a 1 but at two places 13 and 18 both starting points result in 1xx7xx9xx3xx(repeating) the other sequence is 8426 🙂 really loved the puzzle

[@PixelatedPenfold]

I think I need new glasses. I read the title of this as "The Arthritic Snake"

[@lewsouth1539]

Pardon me while I geek out.... The digits on the snake are the final digits of the Lucas numbers, which form a Fibonacci-like sequence: 2, 1, 3, 4, 7, 11, 18, 29, 47, 76, 123, 199, 322, 521, 843, 1364, ... I hadn't realized before that there are no multiples of 5 in the sequence, or that the cycle of final digits was so short (12 digits). (In the Fibonacci sequence, the cycle is 60 digits long, and includes all 10 digits.)

[@whitesoxMLB]

*already has all digits written out in order inside the snake* Simon: Better use 6 cells of elaborate pencil marking to remember the order. I absolutely must not touch these pencil marks at all costs.

[@crhodgkin]

This may seem like an odd request (and I don’t know if it would even be possible or feasible), but could there be a way to import the puzzles from the apps (which I agree, are phenomenal) into Sudokupad for some of the puzzles where I may want more colors/options for difficult solves? I do that already with the classic and chess ones (and refer to the apps for the smart hints when needed), but I can’t do that for any of the other variants.

[@100beep5]

There are, in fact, two digits that work. Starting with the 3, however, is broken for other reasons.

[@gi0nbecell]

Very good idea to mark down the snake sequence. But the constant interference with the solve was… strange. I screamed at my screen, not for any sudoku Simon failed to notice, but “Snipping tool!” (Yes, I know there is better software, I for instance like Greenshot, but let’s keep on board Windows software do the trick). Just snip the sequence from row 1 (because it’s more condensed than the former column 9+8 thing), and place it somewhere on screen for reference. Just as a tip if something like that is ever needed again, and it’s more convenient than opening a text editor )or the Windows notes app), which would also be a valid solution for taking reference notes during such a solve. Now, writing this, I would in fact say that the Notes app would be the most versatile one: It looks like a small piece of paper to scribble notes on, and could be easily implemented on the OBS overlay for the video if needed. And it could help to keep track of ideas or sequences that can’t be easily pencil marked - especially for the audience.

[@toddbiesel4288]

I believe that all possible gray cells were given.

[@MLWJ1993]

Simon, you can predict the future! 😱 Joking, you forgot to delete the 7 after your excursion into some logic.

[@robertcousins2274]

12:09. Simon is always faster than me, unless its some new rule set. But I did the math to figure out there was only one set of snake that would work before I started the timer.

[@77kaczka77]

Straight and gorgeous

[@purpleli4760]

Me: pulls up Excel

[@stumbling]

Is the snake an Adder or a Modulo Constrictor? :P

[@TheBranDingo]

I love the video, but it seems like the quality isn't what it used to be. I wonder if Simon is recording at 720 then upscaling to 1080, or something like that.

[@thefallenarm589]

I'm wondering if there's a clearer rule for snake than "not touching even diagonnally" ; because obviously snake is touching itself diagonnally everytime it turns (like 1 & 9 in box 1 for example).

[@Nic0rasu]

Congratulations you found a Pisano period

[@Rubrickety]

I'll bet I'm not the only solver who took a brief break near the beginning to write a snippet of Python code to determine which starts were valid. 🙂

[@abraxasnl]

17:40. Simon, don’t let anyone tell you your snake is stubby or inadequate.

[@HeroOfRhyme]

I love snake Sudokus

[@solfeinberg437]

The snake can't touch itself. Don't touch yourself, snake. Don't touch your snake, self.