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 641st Shanethegamer 🇺🇸 790 89 457ms 26 Jul 2023 642nd ashtraypettingzoo 🇺🇸 789 19 2ms 3 Apr 2023 642nd AlephSquirrel 789 19 2ms 8 Nov 2025 644th MeWhenI 🇻🇦 789 63 107ms 16 Nov 2022 645th MeWhenI 🇻🇦 789 83 3ms 10 Sep 2022 646th kkoenig 789 111 274ms 5 Jan 2024 647th prplz 🇦🇺 786 46 260ms 24 Jan 2021 647th TimCurwick 🇺🇸 786 46 251ms 26 Jan 2021 647th SirBogman 🇺🇸 786 46 230ms 2 Feb 2024 650th SirBogman 🇺🇸 786 91 38ms 3 Jun 2025 651st RDShah 785 64 10ms 17 Jan 2021 651st andre-lameirinhas 🇵🇹 785 64 10ms 22 Feb 2021 651st stertooy 🇧🇪 785 64 10ms 10 Jun 2024 651st Terobero 785 64 20ms 6 Sep 2024 651st moustave 785 64 11ms 5 May 2025 651st Code-Coder-coder 785 64 11ms 27 days ago 651st Lv0Sys 🇵🇱 785 64 10ms 18 days ago 658th Yewzir 🇧🇪 784 82 99ms 28 Mar 2024 659th Shanethegamer 🇺🇸 782 63 430ms 2 Jul 2021 660th Waffle3z 781 54 37ms 19 Jan 2021 660th KatieLG 🇬🇧 781 54 38ms 9 Jan 2023 660th Andriamanitra 🇫🇮 781 54 47ms 20 Jul 2023 663rd DialFrost 🇸🇬 780 142 1,630ms 13 Sep 2025 664th Shanethegamer 🇺🇸 778 106 33ms 20 Jan 2025 665th rak1507 🇬🇧 777 60 9ms 20 Jan 2021 665th Shanethegamer 🇺🇸 777 60 9ms 26 Sep 2021 665th duckyluuk 🇳🇱 777 60 9ms 4 Oct 2024 668th anter69 🇭🇺 776 59 982ms 24 Feb 2023 668th SirBogman 🇺🇸 776 59 1,152ms 10 Jun 2024 670th NewDefectus 🇮🇱 774 25 4ms 25 Oct 2021 671st scpchicken 🇵🇼 774 48 3ms 15 Dec 2022 672nd commandblockguy 🇺🇸 774 62 425ms 15 Jan 2024 673rd Shanethegamer 🇺🇸 774 93 68ms 12 Jan 2022 674th ovs-code 🇩🇪 774 142 12ms 31 Mar 2023 675th TobyBoyne 🇬🇧 773 65 10ms 21 Jan 2021 675th 77Tigers 773 65 30ms 1 Mar 2021 675th knutae 🇳🇴 773 65 10ms 29 Jun 2021 675th ehulinsky 🇺🇸 773 65 13ms 10 Nov 2021 675th guilhem-roy 🇫🇷 773 65 10ms 28 Feb 2022 675th martinnorling 🇸🇪 773 65 10ms 8 Mar 2022 675th fgrosshans 🇫🇷 773 65 11ms 12 Jul 2022 675th IshanPanpaliya 773 65 10ms 3 May 2023 675th nooberitess 773 65 11ms 8 Apr 2025 675th robin-scragg 773 65 10ms 21 Oct 2025 685th MeWhenI 🇻🇦 772 59 701ms 15 Sep 2025 686th c0d3-4-F00d 🇩🇪 772 70 2ms 18 Mar 2022 686th Alex-x90 🇺🇸 772 70 2ms 6 Mar 2023 686th dokutan 772 70 5ms 18 Jul 2025 689th mousetail 🇳🇱 771 98 116ms 3 Oct 2024 690th MeWhenI 🇻🇦 770 47 259ms 28 Jan 2023 691st LostSyntax21 🇬🇧 767 55 62ms 2 Oct 2024 692nd MeWhenI 🇻🇦 767 89 104ms 25 Dec 2022 693rd emgordon154 766 32 53ms 19 Oct 2025 694th Steffan153 🇫🇮 765 51 80ms 18 Dec 2022 695th retrohun 765 63 102ms 23 Jan 2023 696th Shanethegamer 🇺🇸 765 65 108ms 22 May 2021 697th lynn 765 78 150ms 16 Nov 2021 698th rucin93 🇵🇱 764 60 127ms 9 Aug 2024 699th Waffle3z 764 61 9ms 20 Jan 2021 699th didion0 🇺🇸 764 61 9ms 9 Feb 2021 699th KrausRaus 🇺🇸 764 61 10ms 19 Feb 2021 699th tayloia 🇬🇧 764 61 8ms 29 May 2022 703rd MeWhenI 🇻🇦 764 108 27ms 7 Jun 2023 704th ScottHamper 762 90 446ms 22 days ago 705th ArmaanAS 761 66 11ms 4 Apr 2021 705th quimey 761 66 11ms 23 Jun 2023 705th solisolu 761 66 19ms 27 Oct 2025 708th albanian-laundromat 759 60 718ms 1 Oct 2025 709th SirBogman 🇺🇸 759 86 115ms 24 Jan 2021 709th strout 759 86 124ms 15 Dec 2023 711th antimon2 🇯🇵 758 65 635ms 19 Jan 2021 712th GolfingSuccess 🇬🇷 758 71 6ms 16 Oct 2023 712th Yewzir 🇧🇪 758 71 3ms 19 Nov 2025 714th kcinnu 🇱🇹 758 146 1,731ms 17 May 2024 715th duckyluuk 🇳🇱 756 73 7ms 16 Dec 2024 716th janbehrens 🇩🇪 756 93 464ms 24 Mar 2022 717th Shanethegamer 🇺🇸 754 63 4ms 13 Aug 2024 717th emgordon154 754 63 4ms 25 Aug 2024 719th olivermrose 🇺🇸 753 56 37ms 21 Sep 2021 720th lynn 753 85 1,315ms 12 Sep 2021 First Prev 641–720 of 1,891 Next Last