The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 26 hours. Why not try and solve them ahead of time?
Fibonacci in C# in chars. 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 Chars Time Submitted 152nd bpharaldsson 864 59 354ms 4 Feb 2026 162nd Bobini1 🇵🇱 850 60 375ms 21 Nov 2021 162nd JDiLenarda 🇫🇷 850 60 366ms 21 Nov 2021 162nd najs91 850 60 409ms 21 Nov 2021 162nd yzhs 🇩🇪 850 60 390ms 21 Nov 2021 162nd joharasmus 🇸🇪 850 60 363ms 19 Jul 2022 162nd JaroPolhosDev 850 60 358ms 13 Sep 2023 162nd GarethSpring 850 60 373ms 19 Sep 2023 162nd mqtze 850 60 382ms 21 Sep 2023 162nd puddnova 850 60 377ms 22 Oct 2024 162nd michelebastione 🇮🇹 850 60 390ms 13 Aug 2025 162nd Matter1024 🇮🇳 850 60 374ms 6 hours ago 173rd PatrickKocken 836 61 373ms 21 Nov 2021 173rd TeDeMos 836 61 364ms 21 Nov 2021 173rd castur1 836 61 339ms 27 Jan 2022 173rd centrolutions 836 61 363ms 24 Nov 2022 173rd dorschmeister 836 61 371ms 19 May 2023 173rd fkantelberg 836 61 368ms 15 Jul 2023 173rd josephdwalker 836 61 378ms 14 Nov 2023 173rd epic-programmer-guy 836 61 361ms 25 Dec 2023 173rd codewrite 🇬🇧 836 61 401ms 19 Apr 2025 173rd Alex-Huggett 🇬🇧 836 61 355ms 13 Sep 2025 183rd jahakari 823 62 368ms 21 Nov 2021 183rd MichalMarsalek 🇨🇿 823 62 373ms 29 Nov 2021 183rd owen-c-parker 🇺🇸 823 62 385ms 25 Nov 2022 183rd Mezzofloat 823 62 365ms 24 Aug 2023 183rd nyoshe 823 62 353ms 10 Oct 2023 183rd hippopotam00sehead 🇨🇦 823 62 349ms 11 Sep 2024 183rd Stockoh 🇫🇷 823 62 423ms 4 Nov 2024 183rd desecaw13 823 62 437ms 24 Jan 2025 191st ILMTitan 810 63 367ms 21 Nov 2021 191st Domicnt 810 63 361ms 1 Jan 2022 191st CedricGebistorf 810 63 392ms 3 Feb 2022 191st ChrisTheisen 810 63 371ms 13 Dec 2022 191st TimJackMaster 810 63 352ms 25 Jan 2023 191st gazle 810 63 375ms 25 Apr 2024 197th muztanger 797 64 371ms 21 Nov 2021 197th Xwilarg 🇫🇷 797 64 366ms 21 Nov 2021 197th Ripick 797 64 395ms 30 Apr 2023 197th usernamethatisnttaken 797 64 366ms 6 Sep 2023 197th Mikey-Beep 🇬🇧 797 64 369ms 24 Jul 2025 202nd Andre3582 785 65 371ms 21 Nov 2021 202nd enbyte 785 65 357ms 21 Nov 2021 202nd MLPdiscord 785 65 374ms 6 Jan 2022 202nd Nickmiste 785 65 376ms 13 Nov 2022 202nd mqyhlkahu 785 65 366ms 10 Sep 2023 202nd trinityy-7 785 65 382ms 6 Mar 2024 202nd msbranicky 785 65 369ms 3 Jul 2024 209th aaronze 🇦🇺 773 66 378ms 21 Nov 2021 209th elephantpanda 773 66 388ms 26 Aug 2022 209th eshilo-draper 773 66 375ms 5 Oct 2022 209th heanyang1 773 66 374ms 22 Apr 2025 209th jacekwladzinski 773 66 415ms 2 Oct 2025 209th dpethes 773 66 468ms 10 Dec 2025 215th TheMickeyMouse 761 67 352ms 21 Nov 2021 215th aDwarfNamedUrist 761 67 377ms 21 Nov 2022 215th glatzert 761 67 385ms 12 May 2023 215th Sciman101 761 67 369ms 15 May 2023 215th eiburns 761 67 356ms 7 Sep 2023 215th rollershutter 761 67 342ms 29 Jan 2025 215th kevinnaviapaiva 761 67 353ms 19 Feb 2025 222nd jcheritat 750 68 370ms 21 Nov 2021 222nd PhonicCanine 750 68 368ms 21 Nov 2021 222nd Gpopcorn 750 68 358ms 31 Mar 2022 222nd Mortis66666 750 68 368ms 27 May 2022 222nd 104210 750 68 383ms 12 Sep 2022 222nd Pyro569 750 68 374ms 31 Jul 2023 228th martinnorling 🇸🇪 739 69 370ms 15 Feb 2022 228th PyryL 🇫🇮 739 69 378ms 23 Aug 2024 228th Flix7dev 🇧🇪 739 69 365ms 21 Oct 2025 231st Skellybob56 729 70 367ms 10 Nov 2025 232nd Cbrt74088 718 71 353ms 21 Nov 2021 232nd MrGraduate 718 71 369ms 21 Nov 2021 232nd ccolella-mdc 718 71 371ms 12 Oct 2023 235th charliegaming 708 72 385ms 3 Oct 2023 235th jtaxen 708 72 382ms 30 Mar 2024 235th JarrodCope 708 72 356ms 19 Apr 2024 235th Zach1031 708 72 389ms 15 Nov 2025 239th ericlangedijk 🇸🇮 699 73 374ms 6 Mar 2022 239th xbxbxb007 699 73 362ms 11 Jan 2024 First Prev 161–240 of 330 Next Last