The Calendar hole will go live in approximately 5 days. Why not try and solve it ahead of time?
Collatz 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 634th FlorianCassayre 🇫🇷 874 61 10ms 27 Sep 2022 634th Mazn3k 874 61 10ms 1 Feb 2023 634th tvcv901 874 61 10ms 22 Mar 2023 634th unfinishedprogram 874 61 10ms 19 Jul 2023 634th snoozingnewt 🇨🇦 874 61 10ms 23 Sep 2023 634th funnyboy-roks 874 61 10ms 9 May 2024 634th bac0id 874 61 10ms 29 Jun 2024 634th madex 🇩🇪 874 61 10ms 9 Jul 2024 634th FortuiteMan 🇫🇷 874 61 9ms 10 Oct 2024 634th RobertHoeh 874 61 13ms 5 Apr 2025 634th LvLError 874 61 10ms 29 May 2025 634th miles-evan 874 61 10ms 5 Aug 2025 634th alexsave 874 61 10ms 13 Oct 2025 654th dokutan 873 62 5ms 28 Apr 2025 655th NerdyMcNerd42 873 64 19ms 26 Oct 2022 655th tpasfieldERAU 873 64 23ms 14 Nov 2022 655th CheeseCake628 🇳🇴 873 64 22ms 6 Jan 2023 655th adamnielson42 🇺🇸 873 64 19ms 25 Apr 2023 655th nathsou 🇫🇷 873 64 19ms 2 Sep 2023 655th zwxzwxzwx21 873 64 25ms 30 Jan 2024 655th steffan-polygolf 873 64 19ms 8 Mar 2024 655th Jacob385 873 64 57ms 4 Apr 2024 655th gallium-gonzollium 873 64 28ms 26 Aug 2024 664th Shanethegamer 🇺🇸 873 66 172ms 4 May 2022 664th scpchicken 🇵🇼 873 66 254ms 5 May 2022 664th sisyphus-ppcg 🇦🇺 873 66 174ms 6 May 2022 664th Natanaelel 🇸🇪 873 66 144ms 15 Jun 2022 664th Z-snails 873 66 254ms 27 Feb 2023 664th Jeremy-Stafford 873 66 258ms 27 Feb 2023 664th alomiF 873 66 293ms 1 Sep 2023 664th btnlq 873 66 145ms 17 Oct 2023 672nd johnnythedoggie 873 72 91ms 13 May 2022 672nd kaascevich 873 72 90ms 8 Jul 2025 674th DialFrost 🇸🇬 873 73 83ms 3 Jun 2025 675th HPWiz 🇳🇿 872 49 249ms 4 May 2022 675th JayXon 🇺🇸 872 49 254ms 5 May 2022 675th Steffan153 🇫🇮 872 49 287ms 10 Dec 2022 675th ovs-code 🇩🇪 872 49 389ms 24 Oct 2023 675th sean-niemann 🇺🇸 872 49 271ms 12 Jul 2024 680th DialFrost 🇸🇬 872 86 40ms 24 Oct 2024 680th stefangimmillaro 872 86 39ms 14 Jan 2025 682nd c0d3-4-F00d 🇩🇪 872 89 370ms 5 May 2022 682nd fkantelberg 872 89 340ms 15 Jul 2023 682nd bac0id 872 89 336ms 26 Sep 2023 682nd TRexOnGit 872 89 378ms 16 Feb 2024 686th emgordon154 872 96 105ms 22 days ago 687th inventshah 872 97 58ms 6 May 2022 687th roupiq 🇵🇱 872 97 55ms 22 Nov 2023 689th MeWhenI 🇻🇦 872 109 278ms 9 Feb 2023 690th janbehrens 🇩🇪 871 90 442ms 21 Apr 2023 690th Yewzir 🇧🇪 871 90 426ms 22 Apr 2023 690th Ripick 871 90 439ms 27 Nov 2024 690th emgordon154 871 90 368ms 16 days ago 694th AlephSquirrel 870 80 12ms 20 Apr 2023 694th ashtraypettingzoo 🇺🇸 870 80 15ms 1 Apr 2024 696th GolfingSuccess 🇬🇷 869 71 2ms 5 May 2022 696th emplv 🇱🇻 869 71 2ms 5 May 2022 696th JayXon 🇺🇸 869 71 2ms 7 May 2022 696th m-tkach 🇺🇦 869 71 2ms 15 May 2022 696th nwellnhof 🇩🇪 869 71 2ms 5 Jun 2022 696th Irratix 🇳🇱 869 71 2ms 13 Jun 2022 696th michael-pruglo 🇺🇦 869 71 2ms 13 Jul 2022 696th stefangimmillaro 869 71 2ms 2 Jun 2023 696th kkoenig 869 71 2ms 21 Dec 2023 696th JohandeRuiter 🇳🇱 869 71 2ms 14 Sep 2024 696th masinag 🇮🇹 869 71 2ms 6 Oct 2024 707th dokutan 868 82 23ms 1 Jul 2024 708th nwellnhof 🇩🇪 867 53 6ms 4 May 2022 708th GrayJoKing 🇦🇺 867 53 7ms 6 May 2022 710th albanian-laundromat 867 73 611ms 9 days ago 711th dieggsy 867 97 28ms 8 Oct 2024 712th ovs-code 🇩🇪 867 133 42ms 8 Jul 2024 713th Andriamanitra 🇫🇮 866 54 44ms 21 Jul 2022 713th jared-hughes 866 54 41ms 12 Sep 2022 713th OhmNomNom 866 54 41ms 7 Oct 2022 713th olleicua 🇺🇸 866 54 42ms 21 Jan 2024 713th LostSyntax21 🇬🇧 866 54 40ms 12 Mar 2025 713th AbrahamJLR 🇻🇪 866 54 44ms 4 Jun 2025 713th vishal-mohanty 866 54 40ms 25 Aug 2025 720th GolfingSuccess 🇬🇷 866 57 819ms 29 Aug 2025 First Prev 641–720 of 3,482 Next Last