The Calendar hole will go live in approximately 11 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 800th dokutan 787 92 338ms 24 Mar 2025 802nd Yewzir 🇧🇪 786 39 36ms 7 May 2024 802nd codereport 🇨🇦 786 39 35ms 21 Apr 2025 802nd Chara-0x 786 39 40ms 18 Sep 2025 805th stefangimmillaro 786 86 3,542ms 4 Nov 2024 806th didion0 🇺🇸 785 50 8ms 16 Feb 2022 806th Natanaelel 🇸🇪 785 50 8ms 3 Jan 2024 806th weliveinhell 🇭🇹 785 50 8ms 11 Jan 2024 806th inverseLorentz 🇦🇺 785 50 9ms 1 Apr 2024 806th JOrE20 🇺🇸 785 50 9ms 15 Nov 2025 811th annaproxy 785 65 3ms 3 Oct 2022 812th stellartux 784 48 355ms 1 Jan 2024 813th Shanethegamer 🇺🇸 784 65 6ms 19 Dec 2023 813th Steffan153 🇫🇮 784 65 5ms 20 Dec 2023 815th jared-hughes 781 139 430ms 24 Sep 2025 816th stefangimmillaro 781 159 29ms 4 May 2023 817th blaztoma 🇱🇹 779 39 254ms 25 days ago 818th ZakkkkAttackkkk 🇵🇭 779 55 9ms 30 Jan 2022 818th Emutis 🇱🇹 779 55 11ms 27 Oct 2024 820th hamhub7 779 93 377ms 3 Aug 2022 820th MeWhenI 🇻🇦 779 93 406ms 15 Oct 2022 822nd DialFrost 🇸🇬 777 68 6ms 7 Dec 2024 822nd pardouin 🇫🇷 777 68 5ms 20 Mar 2025 824th kimbo 🇺🇸 777 151 280ms 25 Dec 2022 825th rak1507 🇬🇧 776 52 31ms 29 Jan 2022 826th Shanethegamer 🇺🇸 776 59 122ms 29 Jan 2022 826th Z-snails 776 59 129ms 28 Feb 2023 828th jared-hughes 774 307 22ms 8 Jul 2024 829th inventshah 773 22 2ms 8 May 2022 830th KatieLG 🇬🇧 773 64 956ms 16 Oct 2022 831st CheeseCake628 🇳🇴 772 50 330ms 18 Oct 2025 832nd Shanethegamer 🇺🇸 771 58 13ms 29 Jan 2022 833rd ovs-code 🇩🇪 771 82 97ms 14 Oct 2022 834th codingisgreatbutiamnot 769 51 8ms 25 Jul 2024 835th Yax42 🇫🇷 769 141 422ms 4 Oct 2025 836th MeWhenI 🇻🇦 768 49 459ms 15 Feb 2023 837th dokutan 767 153 288ms 24 Mar 2025 838th petroselo 765 56 9ms 12 Apr 2022 838th HumanoidCPU 765 56 15ms 27 May 2024 838th kevinnaviapaiva 765 56 9ms 19 Dec 2024 838th wobblybits 765 56 10ms 19 Aug 2025 842nd brimstonetrader 763 60 125ms 10 Jan 2024 842nd YAJUE114514 763 60 147ms 23 Jul 2025 844th Yewzir 🇧🇪 763 102 154ms 7 May 2024 845th LeeCamp 762 27 35ms 10 Feb 2022 846th snoozingnewt 🇨🇦 762 154 274ms 29 Oct 2025 847th pardouin 🇫🇷 760 51 62ms 13 Sep 2024 848th Stockoh 🇫🇷 757 51 342ms 23 Jun 2024 849th DialFrost 🇸🇬 757 164 111ms 4 days ago 850th SirBogman 🇺🇸 756 26 38ms 10 Sep 2022 850th Herbert00709 🇵🇱 756 26 38ms 21 Feb 2024 852nd SirFireball3521 754 52 9ms 3 Nov 2022 852nd albanian-laundromat 754 52 9ms 26 days ago 854th iczelia 🇩🇪 752 52 27ms 14 Oct 2025 855th Terobero 752 57 12ms 21 Aug 2024 855th Mick-Travis 752 57 11ms 8 Dec 2024 857th pardouin 🇫🇷 752 84 108ms 8 Mar 2025 858th MeWhenI 🇻🇦 752 156 266ms 10 Feb 2023 859th ovs-code 🇩🇪 751 32 129ms 29 Dec 2023 859th Steffan153 🇫🇮 751 32 118ms 11 Mar 2024 861st Jeremy-Stafford 750 61 124ms 28 Feb 2023 861st inverseLorentz 🇦🇺 750 61 124ms 23 Apr 2024 863rd dokutan 750 83 455ms 22 Sep 2025 864th pardouin 🇫🇷 749 68 5ms 26 Apr 2025 865th MeWhenI 🇻🇦 749 219 110ms 16 Aug 2024 866th dokutan 748 41 51ms 18 Mar 2025 867th Alex-x90 🇺🇸 747 147 571ms 6 May 2024 868th ovs-code 🇩🇪 746 161 141ms 21 Apr 2025 869th snoozingnewt 🇨🇦 745 47 701ms 21 Nov 2025 870th MeWhenI 🇻🇦 745 60 11ms 29 Jan 2022 871st Shanethegamer 🇺🇸 744 85 97ms 14 Oct 2022 871st edsrzf 🇳🇿 744 85 102ms 30 Apr 2025 873rd DialFrost 🇸🇬 744 150 13ms 4 days ago 874th KasperKivimaeki 🇫🇮 743 154 2ms 3 Sep 2025 875th Steffan153 🇫🇮 742 68 41ms 29 Aug 2024 876th nipzu 741 162 135ms 2 Apr 2024 877th dokutan 739 67 930ms 18 Mar 2025 878th dpinchbe 735 28 33ms 6 Sep 2024 879th Waffle3z 733 189 2ms 29 Jan 2022 880th MeWhenI 🇻🇦 731 53 65ms 5 Apr 2025 First Prev 801–880 of 1,982 Next Last