The Calendar hole will go live in approximately 13 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 MeWhenI 🇻🇦 789 63 107ms 16 Nov 2022 642nd MeWhenI 🇻🇦 789 83 3ms 10 Sep 2022 643rd kkoenig 789 111 274ms 5 Jan 2024 644th prplz 🇦🇺 786 46 260ms 24 Jan 2021 644th TimCurwick 🇺🇸 786 46 251ms 26 Jan 2021 644th SirBogman 🇺🇸 786 46 230ms 2 Feb 2024 647th SirBogman 🇺🇸 786 91 38ms 3 Jun 2025 648th RDShah 785 64 10ms 17 Jan 2021 648th andre-lameirinhas 🇵🇹 785 64 10ms 22 Feb 2021 648th stertooy 🇧🇪 785 64 10ms 10 Jun 2024 648th Terobero 785 64 20ms 6 Sep 2024 648th moustave 785 64 11ms 5 May 2025 648th Code-Coder-coder 785 64 11ms 23 days ago 648th Lv0Sys 🇵🇱 785 64 10ms 14 days ago 655th Yewzir 🇧🇪 784 82 99ms 28 Mar 2024 656th Shanethegamer 🇺🇸 782 63 430ms 2 Jul 2021 657th Waffle3z 781 54 37ms 19 Jan 2021 657th KatieLG 🇬🇧 781 54 38ms 9 Jan 2023 657th Andriamanitra 🇫🇮 781 54 47ms 20 Jul 2023 660th DialFrost 🇸🇬 780 142 1,630ms 13 Sep 2025 661st Shanethegamer 🇺🇸 778 106 33ms 20 Jan 2025 662nd rak1507 🇬🇧 777 60 9ms 20 Jan 2021 662nd Shanethegamer 🇺🇸 777 60 9ms 26 Sep 2021 662nd duckyluuk 🇳🇱 777 60 9ms 4 Oct 2024 665th anter69 🇭🇺 776 59 982ms 24 Feb 2023 665th SirBogman 🇺🇸 776 59 1,152ms 10 Jun 2024 667th NewDefectus 🇮🇱 774 25 4ms 25 Oct 2021 668th scpchicken 🇵🇼 774 48 3ms 15 Dec 2022 669th commandblockguy 🇺🇸 774 62 425ms 15 Jan 2024 670th Shanethegamer 🇺🇸 774 93 68ms 12 Jan 2022 671st ovs-code 🇩🇪 774 142 12ms 31 Mar 2023 672nd TobyBoyne 🇬🇧 773 65 10ms 21 Jan 2021 672nd 77Tigers 773 65 30ms 1 Mar 2021 672nd knutae 🇳🇴 773 65 10ms 29 Jun 2021 672nd ehulinsky 🇺🇸 773 65 13ms 10 Nov 2021 672nd guilhem-roy 🇫🇷 773 65 10ms 28 Feb 2022 672nd martinnorling 🇸🇪 773 65 10ms 8 Mar 2022 672nd fgrosshans 🇫🇷 773 65 11ms 12 Jul 2022 672nd IshanPanpaliya 773 65 10ms 3 May 2023 672nd nooberitess 773 65 11ms 8 Apr 2025 672nd robin-scragg 773 65 10ms 21 Oct 2025 682nd c0d3-4-F00d 🇩🇪 772 70 2ms 18 Mar 2022 682nd Alex-x90 🇺🇸 772 70 2ms 6 Mar 2023 682nd dokutan 772 70 5ms 18 Jul 2025 685th mousetail 🇳🇱 771 98 116ms 3 Oct 2024 686th MeWhenI 🇻🇦 770 47 259ms 28 Jan 2023 687th MeWhenI 🇻🇦 770 59 701ms 15 Sep 2025 688th MeWhenI 🇻🇦 767 89 104ms 25 Dec 2022 689th emgordon154 766 32 53ms 19 Oct 2025 690th LostSyntax21 🇬🇧 766 55 62ms 2 Oct 2024 691st retrohun 765 63 102ms 23 Jan 2023 692nd Shanethegamer 🇺🇸 765 65 108ms 22 May 2021 693rd lynn 765 78 150ms 16 Nov 2021 694th rucin93 🇵🇱 764 60 127ms 9 Aug 2024 695th Waffle3z 764 61 9ms 20 Jan 2021 695th didion0 🇺🇸 764 61 9ms 9 Feb 2021 695th KrausRaus 🇺🇸 764 61 10ms 19 Feb 2021 695th tayloia 🇬🇧 764 61 8ms 29 May 2022 699th MeWhenI 🇻🇦 764 108 27ms 7 Jun 2023 700th Steffan153 🇫🇮 763 51 80ms 18 Dec 2022 701st ScottHamper 762 90 446ms 18 days ago 702nd ArmaanAS 761 66 11ms 4 Apr 2021 702nd quimey 761 66 11ms 23 Jun 2023 702nd solisolu 761 66 19ms 27 Oct 2025 705th SirBogman 🇺🇸 759 86 115ms 24 Jan 2021 705th strout 759 86 124ms 15 Dec 2023 707th antimon2 🇯🇵 758 65 635ms 19 Jan 2021 708th GolfingSuccess 🇬🇷 758 71 6ms 16 Oct 2023 708th Yewzir 🇧🇪 758 71 3ms 19 Nov 2025 710th kcinnu 🇱🇹 758 146 1,731ms 17 May 2024 711th albanian-laundromat 757 60 718ms 1 Oct 2025 712th duckyluuk 🇳🇱 756 73 7ms 16 Dec 2024 713th janbehrens 🇩🇪 756 93 464ms 24 Mar 2022 714th Shanethegamer 🇺🇸 754 63 4ms 13 Aug 2024 714th emgordon154 754 63 4ms 25 Aug 2024 716th olivermrose 🇺🇸 753 56 37ms 21 Sep 2021 717th lynn 753 85 1,315ms 12 Sep 2021 718th sean-niemann 🇺🇸 752 61 141ms 17 Jun 2025 719th ScottHamper 752 62 9ms 1 Jun 2021 719th helbling 🇨🇭 752 62 10ms 2 Oct 2024 First Prev 641–720 of 1,887 Next Last