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 801st chordowl 709 92 116ms 17 Mar 2021 802nd aadenboy 🇺🇸 708 86 3ms 5 days ago 803rd SnowballSH 707 71 11ms 12 Feb 2021 803rd Andre3582 707 71 10ms 18 Mar 2021 803rd PhysicDev 🇫🇷 707 71 11ms 20 May 2021 803rd Alban-Boissard 707 71 12ms 10 Jun 2025 807th omurakazuaki 🇯🇵 706 66 9ms 18 Feb 2021 807th BambooleanLogic 🇸🇪 706 66 9ms 22 Aug 2022 807th coreynash 706 66 9ms 21 Oct 2023 807th two-bad 🇬🇧 706 66 9ms 24 Nov 2023 807th dylanarmstrong 706 66 9ms 15 Jan 2024 807th madeforlosers 706 66 9ms 5 Nov 2025 813th Stockoh 🇫🇷 706 68 357ms 24 Jun 2024 814th typeswitch-dev 🇵🇹 705 74 8ms 7 Aug 2023 815th msbranicky 704 65 1,074ms 12 Sep 2023 816th Shanethegamer 🇺🇸 704 91 39ms 16 Jun 2022 817th SnowballSH 703 60 44ms 12 Feb 2021 817th aksyristos 703 60 39ms 28 Feb 2023 817th Lv0Sys 🇵🇱 703 60 56ms 18 days ago 820th MeWhenI 🇻🇦 702 238 12ms 29 Aug 2023 821st MeWhenI 🇻🇦 701 35 49ms 26 Jul 2022 821st jared-hughes 701 35 44ms 31 Jul 2022 821st Natanaelel 🇸🇪 701 35 49ms 18 Aug 2022 824th KasperKivimaeki 🇫🇮 701 125 260ms 3 Oct 2025 825th UnderKoen 🇳🇱 700 134 12ms 20 Jan 2025 826th JayXon 🇺🇸 699 40 57ms 2 Jun 2021 827th jared-hughes 699 44 7ms 31 Jul 2022 828th Shanethegamer 🇺🇸 699 77 13ms 9 Oct 2023 829th JGDoerrer 699 103 474ms 5 Jan 2022 829th tailorspy 699 103 62ms 29 Oct 2023 831st LeeCamp 698 72 11ms 16 Feb 2022 831st LukasFolwarczny 🇨🇿 698 72 11ms 16 Sep 2022 831st CutSandstone 698 72 36ms 8 Jul 2024 834th DialFrost 🇸🇬 696 56 84ms 22 Jul 2024 835th neihousaigaai 696 67 10ms 10 Apr 2021 836th jared-hughes 696 159 1,670ms 16 Sep 2025 837th targrik 695 57 5ms 26 Aug 2025 838th boxjelly 694 94 114ms 21 Jan 2021 838th YAJUE114514 694 94 133ms 24 Jul 2025 840th dokutan 693 99 805ms 24 Sep 2025 841st Espiobest 691 61 37ms 13 Feb 2021 841st DaCuteRaccoon 691 61 40ms 9 Dec 2022 843rd edsrzf 🇳🇿 691 91 19ms 21 Dec 2024 844th MeWhenI 🇻🇦 691 106 341ms 26 Aug 2023 845th Shanethegamer 🇺🇸 690 106 17ms 4 Oct 2024 846th msbranicky 689 95 5ms 11 Aug 2023 847th GolfingSuccess 🇬🇷 688 69 33ms 17 Aug 2024 848th richard-oelze 🇩🇪 688 73 29ms 4 Apr 2021 848th mauro-1 🇮🇹 688 73 9ms 18 Aug 2021 848th gchenfc 688 73 9ms 24 Jan 2022 848th hiichbindermax 688 73 11ms 26 Feb 2022 848th Omega65536 🇩🇪 688 73 11ms 24 Nov 2022 848th sandorstormen 688 73 11ms 18 Feb 2023 848th Mr-McChicken 688 73 11ms 15 Oct 2023 848th Masttest 688 73 10ms 21 Feb 2024 856th Andriamanitra 🇫🇮 687 95 148ms 20 Jul 2023 857th MeWhenI 🇻🇦 685 72 397ms 15 Feb 2023 857th Yewzir 🇧🇪 685 72 483ms 5 Apr 2024 859th msbranicky 685 89 1ms 26 Sep 2023 860th DialFrost 🇸🇬 684 67 131ms 3 Aug 2024 861st madex 🇩🇪 684 79 2ms 11 Jul 2024 862nd AdrienHache 🇫🇷 682 41 50ms 23 Oct 2023 863rd Yewzir 🇧🇪 681 90 327ms 14 Oct 2023 864th jameslindesay 679 74 11ms 24 Feb 2021 864th PkmnQ 679 74 37ms 5 May 2024 864th HumanoidCPU 679 74 11ms 3 Jun 2024 864th RedzGoose 🇦🇺 679 74 13ms 14 Oct 2024 864th yokasuretsu 679 74 10ms 13 Jan 2025 869th I-Love-47 🇺🇦 679 106 63ms 10 Feb 2022 870th dokutan 678 59 3ms 18 Jul 2025 871st Shanethegamer 🇺🇸 678 126 24ms 8 Jul 2021 872nd janbehrens 🇩🇪 673 68 1,067ms 9 Apr 2021 873rd AdrienHache 🇫🇷 673 91 374ms 31 Dec 2023 874th rboath 672 58 88ms 8 Jan 2025 875th msbranicky 672 80 4ms 11 Oct 2023 876th 5quiwyrm 670 54 254ms 5 Dec 2024 877th Trunksistor 🇫🇷 670 75 10ms 25 May 2022 877th celiendonze 🇨🇭 670 75 11ms 16 Jun 2023 877th qwjhvbxi 670 75 10ms 9 Feb 2024 877th wenbang24 670 75 14ms 6 Apr 2024 First Prev 801–880 of 1,891 Next Last