The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Jacobi Symbol 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 320th emgordon154 685 54 52ms 2 Feb 2026 322nd emplv 🇱🇻 685 138 5ms 1 Dec 2023 323rd stefangimmillaro 684 183 371ms 15 Jul 2023 324th Vinterion 681 158 2ms 17 Jun 2024 325th MichalMarsalek 🇨🇿 681 194 588ms 5 Nov 2022 326th Irratix 🇳🇱 679 209 445ms 12 May 2022 327th MeWhenI 🇻🇦 678 169 207ms 23 Jun 2024 327th Shanethegamer 🇺🇸 678 169 169ms 24 May 2025 329th m-tkach 🇺🇦 678 187 16ms 15 Jan 2025 330th MeWhenI 🇻🇦 677 158 118ms 23 Jun 2024 331st lynn 677 263 32ms 23 Jul 2023 332nd FortuiteMan 🇫🇷 676 215 15ms 8 days ago 333rd HPWiz 🇳🇿 675 120 32ms 21 May 2022 333rd albanian-laundromat 675 120 18ms 12 Jul 2025 333rd robin-scragg 675 120 17ms 3 Oct 2025 336th Shanethegamer 🇺🇸 675 213 9ms 4 Oct 2024 337th MeWhenI 🇻🇦 674 123 11ms 25 Nov 2022 338th Yewzir 🇧🇪 672 113 411ms 7 May 2024 339th lynn 669 120 1,237ms 3 Jun 2022 340th nwellnhof 🇩🇪 669 121 30ms 8 Jun 2022 341st uttumuttu 🇫🇮 668 124 10ms 24 May 2022 341st tayloia 🇬🇧 668 124 11ms 11 May 2023 343rd DialFrost 🇸🇬 668 161 2ms 12 Feb 2024 344th SirBogman 🇺🇸 667 93 2ms 30 Oct 2022 344th retrohun 667 93 1ms 9 Nov 2022 346th AlephSquirrel 666 216 6ms 30 Oct 2024 347th nwellnhof 🇩🇪 663 82 127ms 20 May 2022 348th janbehrens 🇩🇪 663 189 453ms 3 Jul 2023 349th snoozingnewt 🇨🇦 661 148 116ms 22 Nov 2025 350th Alex-x90 🇺🇸 661 187 449ms 11 May 2024 351st sean-niemann 🇺🇸 660 94 2ms 14 Aug 2023 352nd MeWhenI 🇻🇦 659 79 72ms 16 Aug 2022 353rd Yax42 🇫🇷 659 190 477ms 30 Jul 2025 354th MeWhenI 🇻🇦 659 208 40ms 4 Sep 2024 355th FortuiteMan 🇫🇷 658 123 10ms 23 Aug 2023 356th elgan65536 🇺🇸 658 238 226ms 9 Mar 2024 357th adriweb 🇫🇷 657 160 27ms 21 Aug 2023 358th MeWhenI 🇻🇦 657 271 33ms 23 Jun 2024 359th stefangimmillaro 656 163 112ms 15 Jul 2023 360th Shanethegamer 🇺🇸 655 185 477ms 7 Jun 2022 361st Shanethegamer 🇺🇸 655 190 147ms 12 May 2022 362nd MeWhenI 🇻🇦 654 189 438ms 23 Jun 2024 363rd janAkali 🇷🇺 654 202 389ms 31 hours ago 364th janbehrens 🇩🇪 653 217 356ms 3 Jul 2023 365th Sakisan 🇧🇪 652 127 11ms 12 May 2022 365th janbehrens 🇩🇪 652 127 12ms 3 Jul 2023 367th roavin 652 165 2ms 26 May 2022 368th CatsAreFluffy 650 190 66ms 30 Dec 2022 369th AlephSquirrel 649 57 52ms 26 Jun 2023 370th MeWhenI 🇻🇦 648 124 1,248ms 25 May 2022 371st CatsAreFluffy 648 166 2ms 25 Jan 2023 371st Alex-x90 🇺🇸 648 166 1ms 14 Dec 2023 373rd itsh01 647 128 13ms 4 Jul 2022 374th Shanethegamer 🇺🇸 647 135 1,030ms 12 May 2022 375th ovs-code 🇩🇪 647 136 1,023ms 5 Jun 2024 376th snoozingnewt 🇨🇦 647 195 110ms 20 Nov 2025 377th MeWhenI 🇻🇦 647 204 403ms 26 Aug 2023 378th roavin 645 194 396ms 26 May 2022 379th inventshah 645 220 418ms 13 May 2022 380th Shanethegamer 🇺🇸 643 125 1,200ms 11 May 2022 380th stefangimmillaro 643 125 1,318ms 15 Jul 2023 382nd Shanethegamer 🇺🇸 643 147 5ms 11 May 2022 383rd edsrzf 🇳🇿 643 213 40ms 30 Dec 2024 384th m-tkach 🇺🇦 642 273 65ms 7 Feb 2023 385th MeWhenI 🇻🇦 641 189 474ms 23 Jun 2024 386th prestosilver 🇺🇸 641 206 365ms 30 hours ago 387th ovs-code 🇩🇪 640 85 122ms 23 May 2025 388th bac0id 640 193 449ms 29 Jun 2024 389th albanian-laundromat 639 132 1,321ms 19 Sep 2025 389th CaedenHarper 🇨🇦 639 132 1,600ms 6 Nov 2025 391st blaztoma 🇱🇹 638 127 30ms 20 days ago 392nd edsrzf 🇳🇿 636 160 5ms 24 Jul 2025 393rd ovs-code 🇩🇪 635 82 36ms 10 Jun 2024 394th GrayJoKing 🇦🇺 634 149 5ms 20 May 2022 394th DialFrost 🇸🇬 634 149 4ms 15 Jan 2024 396th scpchicken 🇵🇼 634 247 241ms 4 Feb 2023 397th KrausRaus 🇺🇸 633 131 14ms 12 May 2022 398th DialFrost 🇸🇬 633 139 7ms 1 Nov 2023 399th annaproxy 632 198 401ms 10 May 2022 400th GrayJoKing 🇦🇺 632 268 20ms 6 Dec 2025 First Prev 321–400 of 728 Next Last