The Calendar hole will go live in approximately 10 days. Why not try and solve it ahead of time?
Catalan Numbers 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 560th pardouin 🇫🇷 878 107 475ms 28 Mar 2025 560th emgordon154 878 107 434ms 28 Mar 2025 560th MeWhenI 🇻🇦 878 107 462ms 28 Mar 2025 560th DialFrost 🇸🇬 878 107 426ms 28 Mar 2025 560th GolfingSuccess 🇬🇷 878 107 485ms 15 days ago 566th saito-ta 🇯🇵 878 131 125ms 20 Nov 2023 567th Bubbler-4 877 46 23ms 11 Feb 2022 567th kgolf 877 46 23ms 14 Feb 2022 569th sisyphus-ppcg 🇦🇺 877 158 5ms 7 Oct 2023 570th Yewzir 🇧🇪 876 134 314ms 28 Oct 2023 570th KasperKivimaeki 🇫🇮 876 134 240ms 12 days ago 572nd GolfingSuccess 🇬🇷 875 40 679ms 29 Aug 2025 573rd primo-ppcg 🇹🇭 875 43 332ms 29 Jan 2022 573rd janbehrens 🇩🇪 875 43 412ms 29 Jan 2022 573rd MarcMush 🇫🇷 875 43 400ms 9 Feb 2022 576th Lydxn 🇨🇦 875 89 149ms 4 Apr 2022 577th LHuitre 874 49 9ms 1 Jun 2022 577th glesnick 874 49 9ms 14 Jul 2022 577th nstearns96 🇬🇧 874 49 11ms 29 Nov 2022 577th fkantelberg 874 49 11ms 6 Aug 2023 577th ei14 874 49 9ms 7 May 2024 577th gallium-gonzollium 874 49 11ms 25 Aug 2024 577th lelbal 874 49 9ms 17 Sep 2024 577th snydej 874 49 9ms 27 Nov 2024 577th StefanHabel 🇨🇦 874 49 9ms 8 Mar 2025 577th bltnppcnt 874 49 11ms 10 Apr 2025 577th michelebastione 🇮🇹 874 49 11ms 8 Aug 2025 577th Chara-0x 874 49 9ms 18 Sep 2025 577th Europe2048 874 49 9ms 18 Oct 2025 577th QuincyNash 🇺🇸 874 49 9ms 22 days ago 577th yujh-yujh 🇬🇸 874 49 9ms 11 days ago 592nd michelebastione 🇮🇹 872 83 393ms 13 Aug 2025 593rd Steffan153 🇫🇮 872 126 456ms 5 May 2024 594th GrayJoKing 🇦🇺 871 36 4ms 31 Jan 2022 595th xsot 🇸🇬 871 128 69ms 13 Jun 2025 596th JayXon 🇺🇸 869 129 2,206ms 14 Sep 2025 597th JayXon 🇺🇸 868 35 257ms 29 Jan 2022 597th stefangimmillaro 868 35 272ms 6 Nov 2023 599th MeWhenI 🇻🇦 868 45 28ms 16 Apr 2023 600th anter69 🇭🇺 868 57 921ms 23 Feb 2023 601st canissimia 🇦🇶 868 150 4,038ms 5 Jun 2023 602nd albanian-laundromat 868 215 10ms 3 days ago 603rd HPWiz 🇳🇿 866 146 1,128ms 12 Oct 2023 604th inventshah 865 127 524ms 5 May 2024 605th ovs-code 🇩🇪 865 135 504ms 30 Sep 2024 606th ovs-code 🇩🇪 865 244 85ms 10 Jan 2023 606th GrayJoKing 🇦🇺 865 244 35ms 11 Jan 2023 608th Steffan153 🇫🇮 864 47 76ms 10 Dec 2022 609th jtaxen 864 53 124ms 16 Jul 2024 610th MeWhenI 🇻🇦 864 59 3ms 1 Oct 2022 610th DialFrost 🇸🇬 864 59 3ms 11 Feb 2023 610th edsrzf 🇳🇿 864 59 3ms 28 Aug 2025 613th ovs-code 🇩🇪 864 72 471ms 27 Feb 2022 613th GrayJoKing 🇦🇺 864 72 470ms 28 Feb 2022 613th Steffan153 🇫🇮 864 72 492ms 11 Feb 2023 616th acotis 864 139 129ms 17 Oct 2025 617th kg583 🇺🇸 863 59 6ms 27 days ago 618th stefangimmillaro 863 136 286ms 9 Sep 2023 618th cduerm 863 136 259ms 19 Sep 2025 618th sean-niemann 🇺🇸 863 136 274ms 21 Sep 2025 621st GrayJoKing 🇦🇺 863 181 134ms 8 May 2022 622nd ovs-code 🇩🇪 861 138 824ms 2 days ago 623rd ovs-code 🇩🇪 861 276 17ms 8 Jul 2024 624th m-tkach 🇺🇦 861 372 102ms 20 Jun 2025 625th DialFrost 🇸🇬 859 71 102ms 16 days ago 625th emgordon154 859 71 116ms 16 days ago 625th GolfingSuccess 🇬🇷 859 71 107ms 9 days ago 628th stefangimmillaro 859 191 113ms 3 May 2023 628th rucin93 🇵🇱 859 191 392ms 4 days ago 630th primo-ppcg 🇹🇭 859 348 12ms 13 Aug 2025 631st lifthrasiir 🇰🇷 858 45 357ms 2 Dec 2024 632nd sean-niemann 🇺🇸 858 128 396ms 4 May 2024 633rd jrm5399 🇰🇿 857 50 9ms 30 Jan 2022 633rd Freddiechang 857 50 9ms 8 Mar 2024 635th 386asm 🇺🇸 857 175 43ms 4 May 2023 636th sean-niemann 🇺🇸 856 218 13ms 3 days ago 637th MeWhenI 🇻🇦 855 23 38ms 25 Jul 2022 637th AlephSquirrel 855 23 55ms 31 Dec 2022 639th Codsilla 🇨🇦 855 44 647ms 3 Nov 2023 639th Daniel-Ellison 855 44 375ms 10 Aug 2025 First Prev 561–640 of 1,983 Next Last