The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 days. Why not try and solve them ahead of time?
Farey Sequence in all languages in bytes. Achievements Cheevos Holes Languages Medals Miscellaneous All Holes 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Multitap Input Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> ALGOL 68 ArkScript Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig 05AB1E APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> ALGOL 68 ArkScript Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig Experimental Language 05AB1E APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Hole All 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Multitap Input Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Experimental Hole Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Bytes Time Submitted 641st Yewzir 🇧🇪 704 137 281ms 5 Jan 2024 642nd DialFrost 🇸🇬 702 60 323ms 16 Jul 2024 643rd weliveinhell 🇭🇹 702 92 2ms 2 Dec 2023 644th agreegious 699 91 11ms 17 Nov 2024 644th ahmetdemirag 🇨🇾 699 91 12ms 1 Feb 2026 646th MeWhenI 🇻🇦 698 101 1,025ms 1 Dec 2023 647th KatieLG 🇬🇧 698 105 467ms 8 Jan 2026 648th saito-ta 🇯🇵 697 141 2,676ms 14 Dec 2023 649th albanian-laundromat 696 270 14ms 8 Dec 2025 650th Shanethegamer 🇺🇸 693 91 74ms 13 Dec 2024 651st MeWhenI 🇻🇦 692 108 4ms 1 Dec 2023 652nd Babafaba 691 92 11ms 22 Oct 2025 652nd Matter1024 🇮🇳 691 92 11ms 3 hours ago 654th Yewzir 🇧🇪 690 98 11ms 9 Jan 2025 655th msbranicky 689 140 301ms 1 Jan 2024 656th Yewzir 🇧🇪 688 83 1,179ms 5 Feb 2025 657th HumanoidCPU 688 124 58ms 5 Mar 2024 658th MateuszPietrzak 🇵🇱 687 94 2ms 7 Dec 2023 659th error256 686 75 1,251ms 11 Feb 2026 660th Yewzir 🇧🇪 686 79 1ms 26 May 2024 661st HumanoidCPU 685 96 2ms 16 Nov 2025 662nd fantaize 685 111 121ms 16 days ago 663rd tatzyr 🇯🇵 684 61 45ms 29 Dec 2024 664th keelimeguy 🇺🇸 684 93 12ms 14 Jun 2025 665th cyrilboyer 🇫🇷 684 141 282ms 14 Dec 2023 666th Shanethegamer 🇺🇸 683 90 85ms 1 Dec 2023 666th commandz0 🇺🇸 683 90 479ms 15 Jan 2024 668th SirFireball3521 682 64 142ms 13 Sep 2024 669th JohandeRuiter 🇳🇱 680 95 2ms 22 Jan 2025 670th mikehanus 677 94 12ms 5 Dec 2023 670th eiburns 677 94 12ms 13 Dec 2023 670th msbranicky 677 94 12ms 1 Jan 2024 670th InigoK 🇺🇸 677 94 11ms 29 Aug 2025 674th SirBogman 🇺🇸 676 54 36ms 1 Dec 2023 675th MeWhenI 🇻🇦 675 82 7ms 1 Dec 2023 676th the-zammers 674 108 129ms 15 Dec 2023 677th Shanethegamer 🇺🇸 673 106 14ms 31 Jan 2024 677th AlephSquirrel 673 106 11ms 24 Jun 2024 679th janbehrens 🇩🇪 670 95 11ms 1 Dec 2023 679th wuzekai518 670 95 11ms 16 Jul 2024 679th CoolBvll 670 95 12ms 13 Jun 2025 679th Techdude01 670 95 11ms 14 Aug 2025 683rd kmathis22 670 113 533ms 6 Dec 2025 684th DialFrost 🇸🇬 669 101 11ms 12 Dec 2024 685th Babafaba 668 92 473ms 22 Oct 2025 686th Ripick 668 94 129ms 24 Jun 2024 687th janbehrens 🇩🇪 667 83 7ms 1 Dec 2023 688th Daniel-Ellison 665 75 487ms 24 days ago 689th HumanoidCPU 665 114 454ms 8 Nov 2025 690th NickTheEASDude 🇺🇸 664 87 13ms 25 Apr 2024 691st BREMAUCY 🇫🇷 663 106 83ms 4 Dec 2023 692nd MichalMarsalek 🇨🇿 661 95 125ms 1 Dec 2023 693rd luuumine 🇫🇷 659 98 2ms 19 Nov 2025 694th tobeannouncd 656 111 128ms 11 Jan 2024 695th MeWhenI 🇻🇦 654 191 7ms 1 Dec 2023 696th msbranicky 653 94 436ms 17 Jan 2024 697th MeWhenI 🇻🇦 650 84 5ms 16 Aug 2024 698th bac0id 649 98 11ms 10 Jan 2025 698th Troon 649 98 11ms 18 Feb 2025 698th JOrE20 649 98 11ms 22 Feb 2026 701st dokutan 648 149 293ms 10 Dec 2024 702nd alomiF 644 113 152ms 6 Dec 2023 703rd cyrilboyer 🇫🇷 644 118 119ms 19 Dec 2023 704th Ripick 643 99 12ms 1 Dec 2023 704th hellwue 643 99 11ms 22 Feb 2024 706th snoozingnewt 🇨🇦 643 150 281ms 15 Oct 2025 707th jbt 642 90 13ms 24 Dec 2023 707th JOrE20 642 90 11ms 27 Jan 2026 709th elgan65536 🇺🇸 640 101 2ms 5 Dec 2023 709th madex 🇩🇪 640 101 2ms 13 Feb 2024 709th Herbert00709 🇵🇱 640 101 2ms 3 Sep 2024 712th Yewzir 🇧🇪 639 92 150ms 27 Mar 2024 713th snoozingnewt 🇨🇦 639 110 80ms 15 Oct 2025 714th dokutan 638 106 11ms 30 Nov 2025 715th gifti258 637 99 69ms 8 Aug 2025 716th AstroOrbis 636 100 11ms 22 Feb 2026 717th janbehrens 🇩🇪 635 91 11ms 1 Dec 2023 717th eranws 635 91 12ms 16 Mar 2024 719th northsuperman 633 102 2ms 24 Mar 2024 720th dokutan 633 104 2ms 26 Oct 2024 First Prev 641–720 of 1,545 Next Last