The Calendar hole will go live in approximately 7 days. Why not try and solve it ahead of time?
Kolakoski Constant in all languages 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 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 Chars Time Submitted 481st neihousaigaai 470 275 565ms 5 Jan 2022 482nd Yewzir 🇧🇪 469 242 353ms 11 Feb 2024 483rd jared-hughes 466 233 2,028ms 17 Jul 2022 484th LukasFolwarczny 🇨🇿 462 126 12ms 16 Sep 2022 485th osmith93 458 127 61ms 10 Jul 2022 486th TheZwierzLF 🇵🇱 457 107 3,076ms 2 days ago 487th Shanethegamer 🇺🇸 457 248 361ms 12 Dec 2021 488th eranws 456 150 44ms 2 Nov 2022 489th janbehrens 🇩🇪 455 150 425ms 3 Dec 2023 490th dokutan 455 249 402ms 21 Aug 2024 491st adamnielson42 🇺🇸 453 93 21ms 20 Nov 2023 492nd yokasuretsu 448 130 31ms 13 Jan 2025 492nd WillowWispy 448 130 13ms 16 Mar 2025 494th LucaArgentiUCF 🇮🇹 448 294 106ms 28 Jan 2021 495th NickTheEASDude 🇺🇸 444 131 188ms 20 Aug 2024 496th h3ra993huskp 🇯🇵 444 291 641ms 24 days ago 497th MeWhenI 🇻🇦 440 399 25ms 10 Jul 2021 498th dokutan 438 219 3,656ms 23 Oct 2024 499th dokutan 438 231 1,242ms 23 Aug 2024 500th hiddicop 🇸🇪 437 112 71ms 29 Jan 2021 501st Shanethegamer 🇺🇸 437 113 248ms 4 Dec 2022 502nd jacekwladzinski 437 133 11ms 9 Oct 2025 503rd madex 🇩🇪 432 250 36ms 27 Oct 2024 504th glesnick 431 135 170ms 18 Aug 2022 505th boxjelly 430 201 145ms 26 Jan 2021 506th jacobly0 🇺🇸 429 275 2ms 21 Sep 2023 507th MeWhenI 🇻🇦 428 223 40ms 3 Sep 2024 508th Pyroan 422 138 98ms 14 May 2025 508th InigoK 🇺🇸 422 138 31ms 25 Aug 2025 510th dokutan 422 226 41ms 24 Aug 2024 511th michelebastione 🇮🇹 419 139 70ms 10 Apr 2021 511th cubed-guy 419 139 24ms 2 Nov 2022 513th dokutan 417 218 6ms 5 May 2024 514th SniperSmiley 🇺🇸 416 140 95ms 30 Jun 2022 514th StefanHabel 🇨🇦 416 140 65ms 21 Apr 2024 516th MeWhenI 🇻🇦 416 209 80ms 13 Dec 2022 517th TheZwierzLF 🇵🇱 412 142 3,009ms 2 days ago 518th RYNO8 410 142 14ms 4 Sep 2021 519th Yewzir 🇧🇪 410 203 69ms 9 Mar 2024 520th MeWhenI 🇻🇦 408 724 9ms 28 Nov 2023 521st albanian-laundromat 404 333 936ms 8 Sep 2025 522nd Yewzir 🇧🇪 403 207 71ms 7 Jul 2023 523rd m-tkach 🇺🇦 401 145 113ms 19 Sep 2021 524th dokutan 400 425 41ms 22 days ago 525th neihousaigaai 398 146 19ms 8 Apr 2021 525th AGoyet 398 146 25ms 29 Jun 2022 527th Yewzir 🇧🇪 397 210 996ms 18 Feb 2024 528th RDShah 396 147 181ms 19 Jan 2021 529th dokutan 392 445 1,653ms 21 Oct 2025 530th dokutan 390 703 10ms 28 Jun 2025 531st MeWhenI 🇻🇦 389 202 13ms 15 Nov 2021 532nd cure-honey 🇯🇵 389 338 112ms 23 Mar 2021 533rd Schmitt-Very-Cool 387 334 1,059ms 1 Oct 2025 534th boxjelly 385 127 647ms 12 Feb 2021 535th Indivicivet 385 151 386ms 26 Oct 2021 536th TheZwierzLF 🇵🇱 383 152 2,153ms 2 days ago 537th Yewzir 🇧🇪 383 205 14ms 11 Nov 2023 538th hiddicop 🇸🇪 380 153 13ms 29 Jan 2021 538th ahmetdemirag 🇨🇾 380 153 476ms 16 Apr 2025 540th aksyristos 370 132 994ms 17 Nov 2024 541st LeeCamp 366 159 17ms 16 Feb 2022 542nd boxjelly 361 161 79ms 21 Jan 2021 542nd za3k 361 161 101ms 28 Oct 2022 544th dokutan 358 390 4ms 1 Apr 2024 545th emgordon154 357 642 4ms 11 Jul 2024 546th aksyristos 355 164 127ms 26 Jan 2023 547th msbranicky 352 166 503ms 17 Jan 2024 548th adamnielson42 🇺🇸 352 194 17ms 25 Apr 2023 549th KatieLG 🇬🇧 352 425 72ms 22 Jan 2023 550th msbranicky 350 166 44ms 19 Aug 2023 551st MeWhenI 🇻🇦 349 180 788ms 15 Sep 2025 552nd MaxElf999 346 168 367ms 27 Sep 2022 553rd zakariamouhid 344 199 57ms 24 Jun 2023 554th MeWhenI 🇻🇦 339 265 1,063ms 12 Nov 2022 555th Yewzir 🇧🇪 337 270 28ms 22 Dec 2023 556th dokutan 329 409 36ms 14 Jun 2024 557th MarcMush 🇫🇷 328 581 4ms 5 Feb 2024 558th bwat2 324 399 551ms 4 Mar 2022 559th Flekay 🇩🇪 321 181 18ms 10 Jul 2025 560th typeswitch-dev 🇵🇹 320 595 6ms 4 Aug 2023 First Prev 481–560 of 1,690 Next Last