The Calendar hole will go live in approximately 9 days. Why not try and solve it ahead of time?
Kolakoski 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 Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz 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 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 Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> 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 ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> 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 ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight 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 Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz 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 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 Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Bytes Time Submitted 375th snoozingnewt 🇨🇦 866 58 20ms 21 days ago 402nd MeWhenI 🇻🇦 866 87 11ms 30 Oct 2021 403rd lukegustafson 🇺🇸 865 53 152ms 17 Jun 2025 404th stefangimmillaro 865 79 97ms 21 Jun 2023 405th janbehrens 🇩🇪 864 43 3ms 18 Jan 2021 406th Shanethegamer 🇺🇸 864 53 1,128ms 23 May 2021 406th MeWhenI 🇻🇦 864 53 996ms 16 Mar 2022 408th GrayJoKing 🇦🇺 864 90 93ms 9 Jun 2022 409th DaCuteRaccoon 863 54 9ms 9 Dec 2022 410th bitsandbeyond 🇳🇱 861 42 238ms 27 Oct 2025 411th primo-ppcg 🇹🇭 861 49 47ms 18 Jan 2022 412th sisyphus-ppcg 🇦🇺 861 56 2ms 12 Jul 2022 413th error256 861 72 62ms 10 days ago 414th DialFrost 🇸🇬 861 76 3ms 14 Sep 2024 415th edsrzf 🇳🇿 859 53 747ms 31 Aug 2025 415th DialFrost 🇸🇬 859 53 800ms 1 Sep 2025 415th xsot 🇸🇬 859 53 849ms 32 hours ago 418th GrayJoKing 🇦🇺 859 96 33ms 18 Jan 2023 418th lynn 859 96 39ms 6 Aug 2023 420th DialFrost 🇸🇬 857 56 404ms 15 Jan 2024 420th Steffan153 🇫🇮 857 56 415ms 16 Jan 2024 420th duckyluuk 🇳🇱 857 56 412ms 27 Mar 2024 423rd Steffan153 🇫🇮 857 63 2ms 23 Mar 2023 423rd stefangimmillaro 857 63 2ms 18 Sep 2023 423rd xsot 🇸🇬 857 63 2ms 6 May 2025 423rd KasperKivimaeki 🇫🇮 857 63 2ms 14 Aug 2025 427th MeWhenI 🇻🇦 857 80 443ms 7 Nov 2025 428th jared-hughes 857 84 64ms 31 Jul 2022 428th inventshah 857 84 77ms 17 Nov 2022 430th primo-ppcg 🇹🇭 857 195 11ms 2 Aug 2023 431st Lydxn 🇨🇦 855 100 25ms 13 Oct 2023 432nd Lydxn 🇨🇦 854 63 2ms 15 Jan 2024 432nd JayXon 🇺🇸 854 63 4ms 29 Jan 2024 432nd rucin93 🇵🇱 854 63 2ms 19 Nov 2025 435th primo-ppcg 🇹🇭 854 78 122ms 27 Mar 2021 435th Shanethegamer 🇺🇸 854 78 125ms 18 Mar 2023 435th Ripick 854 78 172ms 2 Jun 2025 438th sean-niemann 🇺🇸 854 80 95ms 21 Sep 2023 438th Yewzir 🇧🇪 854 80 84ms 16 Nov 2023 440th snoozingnewt 🇨🇦 854 102 126ms 16 days ago 441st nwellnhof 🇩🇪 852 43 206ms 21 Oct 2021 441st primo-ppcg 🇹🇭 852 43 210ms 22 Apr 2022 443rd MeWhenI 🇻🇦 852 84 40ms 29 Apr 2025 444th marcin7Cd 851 59 10ms 16 Jan 2021 444th rak1507 🇬🇧 851 59 10ms 20 Jan 2021 444th AlephSquirrel 851 59 10ms 13 May 2021 444th rschwa6308 🇺🇸 851 59 10ms 28 Jun 2021 444th NewDefectus 🇮🇱 851 59 13ms 25 Oct 2021 444th jacksonhenry3 851 59 13ms 21 Dec 2021 444th NicoAdams 851 59 14ms 21 Dec 2021 444th aksyristos 851 59 11ms 28 Feb 2023 444th BREMAUCY 🇫🇷 851 59 11ms 27 Apr 2023 444th 2011-Chan-Ethan 851 59 10ms 17 Jul 2023 444th MarcMush 🇫🇷 851 59 10ms 12 Feb 2024 444th albanian-laundromat 851 59 13ms 13 Apr 2025 456th Shanethegamer 🇺🇸 851 67 3,743ms 27 Oct 2024 456th pardouin 🇫🇷 851 67 4,270ms 23 Dec 2024 458th MeWhenI 🇻🇦 851 72 400ms 21 Nov 2021 459th kg583 🇺🇸 851 86 9ms 1 Sep 2025 460th ovs-code 🇩🇪 851 138 433ms 17 Feb 2025 461st albanian-laundromat 850 77 9ms 22 Oct 2025 462nd MeWhenI 🇻🇦 849 65 6ms 24 Dec 2024 463rd ovs-code 🇩🇪 849 73 70ms 17 Sep 2023 464th MeWhenI 🇻🇦 848 27 33ms 16 Mar 2022 465th sisyphus-ppcg 🇦🇺 848 89 118ms 25 Jan 2021 465th Bubbler-4 848 89 115ms 1 Jul 2021 467th CatsAreFluffy 847 33 50ms 31 Dec 2022 468th jared-hughes 847 55 9ms 31 Jul 2022 468th emgordon154 847 55 9ms 4 Mar 2025 470th primo-ppcg 🇹🇭 847 85 58ms 18 Jan 2022 470th 09cf 847 85 71ms 24 Sep 2023 472nd emgordon154 845 131 1,782ms 29 Nov 2024 473rd blaztoma 🇱🇹 844 44 3ms 22 Nov 2025 474th dokutan 843 47 5ms 18 Jul 2025 475th Shanethegamer 🇺🇸 843 50 38ms 22 Mar 2023 475th MeWhenI 🇻🇦 843 50 36ms 22 Mar 2023 477th MeWhenI 🇻🇦 843 104 267ms 8 Feb 2023 478th KatieLG 🇬🇧 842 57 411ms 15 Jan 2024 478th kg583 🇺🇸 842 57 371ms 15 Jan 2024 478th GrayJoKing 🇦🇺 842 57 408ms 15 Jan 2024 First Prev 401–480 of 1,891 Next Last