The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 3 days. Why not try and solve them ahead of time?
Van Eck Sequence in all languages 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 321st sean-niemann 🇺🇸 865 71 94ms 30 Dec 2024 322nd DialFrost 🇸🇬 865 76 118ms 30 Nov 2025 322nd snoozingnewt 🇨🇦 865 76 123ms 30 Nov 2025 324th bitsandbeyond 🇳🇱 864 45 698ms 5 Nov 2025 325th primo-ppcg 🇹🇭 864 84 365ms 21 Nov 2021 326th sean-niemann 🇺🇸 862 68 2ms 2 Jan 2025 327th kg583 🇺🇸 861 85 53ms 14 days ago 328th primo-ppcg 🇹🇭 860 36 4ms 1 May 2021 328th HPWiz 🇳🇿 860 36 4ms 2 May 2021 330th Lydxn 🇨🇦 860 46 1,313ms 27 Jun 2023 331st b-illy 🇬🇧 860 56 427ms 7 Sep 2024 332nd MichalMarsalek 🇨🇿 860 61 142ms 15 Nov 2021 332nd GrayJoKing 🇦🇺 860 61 143ms 8 May 2022 332nd prestosilver 🇺🇸 860 61 143ms 5 days ago 335th GrayJoKing 🇦🇺 860 76 8ms 21 Feb 2026 336th jared-hughes 860 169 7ms 17 Mar 2023 337th zacjl 858 81 47ms 14 Feb 2025 338th KasperKivimaeki 🇫🇮 858 110 288ms 29 Sep 2025 339th JayXon 🇺🇸 858 159 1,642ms 15 Sep 2025 340th MeWhenI 🇻🇦 857 170 1,154ms 18 Jan 2026 341st kg583 🇺🇸 856 59 27ms 17 days ago 341st Steffan153 🇫🇮 856 59 29ms 14 days ago 343rd jared-hughes 855 28 33ms 23 Sep 2021 343rd neel11235813 855 28 34ms 4 Mar 2023 345th m-tkach 🇺🇦 855 92 56ms 2 Jan 2022 345th inventshah 855 92 56ms 16 Dec 2022 345th 09cf 855 92 58ms 9 Sep 2023 345th ovs-code 🇩🇪 855 92 54ms 3 Jun 2024 345th KasperKivimaeki 🇫🇮 855 92 72ms 27 Nov 2025 350th dmrichwa 🇺🇸 854 48 12ms 25 Apr 2022 351st marcin7Cd 854 60 11ms 1 May 2021 351st RYNO8 854 60 29ms 29 Aug 2021 351st jared-hughes 854 60 11ms 11 Sep 2022 351st quimey 854 60 12ms 15 Mar 2023 351st janbehrens 🇩🇪 854 60 11ms 17 Jun 2023 351st tobeannouncd 854 60 11ms 18 Sep 2023 351st Hyunwook-Kim-WV 854 60 11ms 7 Aug 2025 351st jacekwladzinski 854 60 31ms 3 Oct 2025 351st edsrzf 🇳🇿 854 60 12ms 25 Nov 2025 351st sisyphus-ppcg 🇦🇺 854 60 28ms 30 Nov 2025 351st lvl1psy 854 60 11ms 3 Jan 2026 351st ryyyn 🇺🇸 854 60 22ms 14 Jan 2026 363rd namelessiw 854 85 388ms 16 Aug 2025 363rd DialFrost 🇸🇬 854 85 394ms 16 Nov 2025 365th GrayJoKing 🇦🇺 853 43 145ms 4 Aug 2024 366th stefangimmillaro 853 72 88ms 7 May 2023 367th GrayJoKing 🇦🇺 850 24 3ms 5 Jun 2025 368th primo-ppcg 🇹🇭 849 72 18ms 22 Jan 2023 369th Shanethegamer 🇺🇸 849 169 1,447ms 28 Apr 2025 370th CaedenHarper 🇨🇦 845 57 444ms 10 Sep 2024 370th DialFrost 🇸🇬 845 57 463ms 30 Dec 2024 372nd yeminghan2021 845 93 61ms 3 Feb 2025 373rd tomtheisen 🇺🇸 844 86 371ms 21 Nov 2021 374th emplv 🇱🇻 843 112 282ms 19 Feb 2022 375th primo-ppcg 🇹🇭 842 47 1,217ms 1 May 2021 375th pardouin 🇫🇷 842 47 1,208ms 10 Sep 2025 377th ovs-code 🇩🇪 841 58 18ms 1 Jul 2024 378th Shanethegamer 🇺🇸 841 73 105ms 13 May 2021 379th Steffan153 🇫🇮 840 46 2ms 20 Jul 2024 379th sean-niemann 🇺🇸 840 46 2ms 28 Apr 2025 381st knyghty 840 61 12ms 17 Feb 2024 381st zacjl 840 61 12ms 11 Sep 2024 381st robin-scragg 840 61 12ms 24 Jul 2025 384th ovs-code 🇩🇪 839 171 1,458ms 9 Mar 2025 385th prplz 🇦🇺 837 44 38ms 1 May 2021 386th duckyluuk 🇳🇱 837 49 10ms 3 Oct 2024 386th blaztoma 🇱🇹 837 49 11ms 6 days ago 388th Shanethegamer 🇺🇸 837 58 2ms 24 May 2021 389th m-tkach 🇺🇦 837 70 2ms 20 Dec 2021 389th inventshah 837 70 2ms 24 Nov 2022 389th ovs-code 🇩🇪 837 70 2ms 12 Feb 2023 389th ListeriaM 837 70 2ms 21 Aug 2023 393rd MeWhenI 🇻🇦 836 94 54ms 8 May 2022 393rd jared-hughes 836 94 59ms 20 Jul 2022 393rd janbehrens 🇩🇪 836 94 55ms 20 Nov 2022 393rd MateuszPietrzak 🇵🇱 836 94 55ms 11 Jan 2024 393rd luuumine 🇫🇷 836 94 58ms 10 Nov 2025 398th stefangimmillaro 835 73 43ms 21 Jun 2023 399th rucin93 🇵🇱 834 44 144ms 3 Aug 2024 400th GrayJoKing 🇦🇺 833 61 32ms 18 Aug 2023 First Prev 321–400 of 1,855 Next Last