The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 4 days. Why not try and solve them ahead of time?
Emirp Numbers in Python 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 473rd Vaekor 444 124 41ms 28 Jul 2023 473rd Alex-Huggett 🇬🇧 444 124 67ms 23 Oct 2024 483rd qiman3 440 125 20ms 24 Jan 2019 483rd decorator-factory 440 125 30ms 24 May 2019 483rd n1LS 440 125 42ms 26 Sep 2019 483rd scrappedsoda 440 125 10ms 31 Oct 2019 483rd tomh1012 440 125 22ms 29 Oct 2020 483rd ritwinnarra 440 125 18ms 11 Jun 2023 483rd hamilton-bonds 440 125 12ms 24 Jul 2025 490th Bibi2424 437 126 35ms 13 May 2019 490th mothcolada 🇺🇸 437 126 73ms 25 Mar 2021 490th DuyTaDinh 437 126 12ms 24 Sep 2021 490th dillon-duncando 437 126 33ms 1 Dec 2021 490th alexjurkiewicz 🇦🇺 437 126 43ms 7 Nov 2023 490th epic-programmer-guy 437 126 20ms 1 Jan 2024 490th jameswmccarty 437 126 23ms 10 Jul 2024 497th OpesMentis 433 127 20ms 22 Mar 2018 497th bkshrader 433 127 15ms 29 Dec 2018 497th danwley 433 127 13ms 5 Jan 2019 497th ay2718 433 127 38ms 13 Aug 2019 497th Phanabani 🇺🇸 433 127 12ms 21 Oct 2020 497th potato-jackson 433 127 15ms 4 Mar 2021 497th LiamKrenn 433 127 14ms 25 Jul 2022 497th nmgetahun 433 127 61ms 9 Dec 2022 497th Ripick 433 127 14ms 1 Feb 2023 506th yokasuretsu 430 128 11ms 13 Apr 2018 506th mackenziem116 430 128 12ms 2 Aug 2018 506th ArturLange 430 128 19ms 5 Sep 2018 506th mvrkws 430 128 19ms 3 Dec 2018 506th matheusnervis 430 128 29ms 15 Jan 2019 506th artieleach 430 128 20ms 12 Dec 2020 506th hymanimy 430 128 26ms 23 Jul 2021 506th Trunksistor 🇫🇷 430 128 29ms 18 May 2022 506th AodhanDalton 430 128 13ms 2 Sep 2022 506th nayakrujul 430 128 16ms 3 Jan 2023 506th mbittner20 430 128 33ms 27 May 2023 506th dgambit 430 128 46ms 8 May 2024 506th ridingqwerty 🇺🇸 430 128 29ms 21 May 2025 506th tejapvk 430 128 11ms 19 Jun 2025 506th Code-Coder-coder 430 128 14ms 11 Oct 2025 521st djtuBIG-MaliceX 426 129 20ms 31 Jan 2018 521st evelyn-fu 426 129 20ms 15 Aug 2018 521st rjomabolla 426 129 15ms 3 Aug 2020 521st jackdonofrio 426 129 29ms 25 Sep 2020 521st TimLeffke 426 129 28ms 15 Aug 2022 521st Cynopolis 426 129 39ms 11 Oct 2023 521st bac0id 426 129 14ms 29 Jun 2024 528th omgardner 423 130 14ms 10 Jul 2019 528th kypi 423 130 49ms 18 Feb 2020 528th vonKrafft 423 130 16ms 26 Mar 2020 528th boxjelly 423 130 15ms 12 Feb 2021 528th TheSmilingTurtle 423 130 50ms 19 May 2022 528th AliceFord 423 130 13ms 2 Jun 2022 528th Wildst 423 130 21ms 2 Nov 2022 528th bobbysq 423 130 70ms 23 Jan 2023 528th JamesTadleyGreen 423 130 18ms 11 Apr 2024 537th ProtD 420 131 109ms 27 Feb 2018 537th ari-gutierrez 420 131 14ms 22 Oct 2018 537th skps2010 420 131 18ms 3 Jan 2019 537th jotslo 🇬🇧 420 131 13ms 11 Jul 2019 537th Guptacos 420 131 27ms 2 Aug 2020 537th Sudoaepothetic 420 131 31ms 5 Dec 2021 537th LogicalJoe 420 131 10ms 14 Mar 2023 537th Eugen-str 420 131 21ms 3 Nov 2023 537th mar-moraes 420 131 12ms 12 Feb 2024 537th wenbang24 420 131 12ms 6 Jul 2024 547th hdformat 417 132 11ms 8 Jun 2020 547th befoster 417 132 28ms 10 Apr 2021 547th martinnorling 🇸🇪 417 132 11ms 2 Feb 2022 547th PeterZaka 417 132 80ms 15 Jan 2023 547th damoc1es 417 132 13ms 16 Apr 2023 552nd axpepper 414 133 27ms 29 Sep 2018 552nd SurplusSineWaves 414 133 31ms 10 Jun 2019 552nd EB-Brown 414 133 55ms 24 Aug 2019 552nd ianpoe 414 133 41ms 20 Apr 2020 552nd Pena86 414 133 25ms 28 Feb 2021 552nd kenny14231 414 133 28ms 5 Aug 2022 552nd omri2001 414 133 21ms 22 Oct 2022 552nd GWStuart 414 133 28ms 21 Nov 2024 552nd RandGuy 414 133 9ms 27 Nov 2025 First Prev 481–560 of 813 Next Last