The Calendar hole will go live in approximately 13 days. Why not try and solve it ahead of time?
Collatz 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 713th Mazn3k 877 61 10ms 1 Feb 2023 713th tvcv901 877 61 10ms 22 Mar 2023 713th unfinishedprogram 877 61 10ms 19 Jul 2023 713th snoozingnewt 🇨🇦 877 61 10ms 23 Sep 2023 713th funnyboy-roks 877 61 10ms 9 May 2024 713th bac0id 877 61 10ms 29 Jun 2024 713th madex 🇩🇪 877 61 10ms 9 Jul 2024 713th FortuiteMan 🇫🇷 877 61 9ms 10 Oct 2024 713th RobertHoeh 877 61 13ms 5 Apr 2025 713th LvLError 877 61 10ms 29 May 2025 713th miles-evan 877 61 10ms 5 Aug 2025 713th alexsave 877 61 10ms 13 Oct 2025 733rd GolfingSuccess 🇬🇷 876 57 819ms 29 Aug 2025 734th MeWhenI 🇻🇦 876 110 278ms 9 Feb 2023 734th edsrzf 🇳🇿 876 110 258ms 28 Nov 2024 734th targrik 876 110 267ms 30 Jun 2025 737th nwellnhof 🇩🇪 875 53 6ms 4 May 2022 737th GrayJoKing 🇦🇺 875 53 7ms 6 May 2022 739th AlephSquirrel 875 80 12ms 20 Apr 2023 739th ashtraypettingzoo 🇺🇸 875 80 15ms 1 Apr 2024 741st c0d3-4-F00d 🇩🇪 875 89 370ms 5 May 2022 741st fkantelberg 875 89 340ms 15 Jul 2023 741st TRexOnGit 875 89 378ms 16 Feb 2024 744th MeWhenI 🇻🇦 874 71 106ms 13 Dec 2022 745th Steffan153 🇫🇮 874 83 446ms 9 Apr 2023 746th ovs-code 🇩🇪 874 85 15ms 11 Dec 2023 747th inventshah 874 97 58ms 6 May 2022 747th roupiq 🇵🇱 874 97 55ms 22 Nov 2023 749th Irratix 🇳🇱 873 72 2ms 4 May 2022 749th m-tkach 🇺🇦 873 72 2ms 4 May 2022 749th jared-hughes 873 72 2ms 6 Jul 2022 749th michael-pruglo 🇺🇦 873 72 2ms 13 Jul 2022 749th Steffan153 🇫🇮 873 72 2ms 3 Jan 2023 749th MeWhenI 🇻🇦 873 72 3ms 7 May 2023 749th ListeriaM 873 72 2ms 22 Aug 2023 749th JohandeRuiter 🇳🇱 873 72 3ms 14 Sep 2024 749th larcherMTT 873 72 2ms 5 Oct 2024 749th snyderek 🇺🇸 873 72 3ms 19 Feb 2025 749th 5quiwyrm 873 72 2ms 29 Jun 2025 749th TeodorDyakov 🇧🇬 873 72 3ms 8 Jul 2025 749th xiaoyiming123 873 72 2ms 12 Jul 2025 762nd ovs-code 🇩🇪 873 83 54ms 1 Jul 2024 763rd Andriamanitra 🇫🇮 872 54 48ms 21 Jul 2022 763rd jared-hughes 872 54 39ms 12 Sep 2022 763rd OhmNomNom 872 54 45ms 7 Oct 2022 763rd olleicua 🇺🇸 872 54 53ms 21 Jan 2024 763rd LostSyntax21 🇬🇧 872 54 63ms 12 Mar 2025 763rd AbrahamJLR 🇻🇪 872 54 58ms 4 Jun 2025 763rd vishal-mohanty 872 54 37ms 25 Aug 2025 770th DialFrost 🇸🇬 872 64 5ms 10 Jul 2024 771st MeWhenI 🇻🇦 872 85 41ms 27 Jun 2022 771st Shanethegamer 🇺🇸 872 85 38ms 15 May 2023 771st albanian-laundromat 872 85 40ms 25 Aug 2025 774th dieggsy 872 97 28ms 8 Oct 2024 775th ulucs 871 35 9ms 8 May 2022 775th bstrat 871 35 9ms 6 Jun 2024 775th wh3n3v3r 🇨🇿 871 35 8ms 18 Nov 2024 778th scpchicken 🇵🇼 871 45 406ms 4 May 2022 778th SirBogman 🇺🇸 871 45 300ms 5 May 2022 780th TFeld00 🇩🇰 871 71 24ms 17 May 2022 780th DialFrost 🇸🇬 871 71 24ms 15 Nov 2022 780th StefanHabel 🇨🇦 871 71 18ms 29 Nov 2022 780th nstearns96 🇬🇧 871 71 18ms 11 Jan 2023 780th hallvabo 🇳🇴 871 71 19ms 7 Feb 2023 780th anter69 🇭🇺 871 71 17ms 21 May 2024 780th rucin93 🇵🇱 871 71 17ms 10 Jul 2024 780th lelbal 871 71 19ms 26 Aug 2025 780th HETHAT 🇩🇿 871 71 23ms 23 Sep 2025 780th 09cf 871 71 17ms 18 Nov 2025 780th blaztoma 🇱🇹 871 71 24ms 23 days ago 780th Languag3 871 71 23ms 13 days ago 792nd ovs-code 🇩🇪 871 133 42ms 8 Jul 2024 793rd CaedenHarper 🇨🇦 869 60 431ms 28 Sep 2025 794th Steffan153 🇫🇮 869 82 1,287ms 23 Feb 2023 795th 123mjb 869 96 356ms 20 Nov 2025 795th noescareno 869 96 406ms 26 days ago 797th Shanethegamer 🇺🇸 869 98 100ms 15 Apr 2025 797th GolfingSuccess 🇬🇷 869 98 111ms 20 days ago 797th DialFrost 🇸🇬 869 98 94ms 17 days ago 800th Frowny 868 38 40ms 5 May 2022 First Prev 721–800 of 3,526 Next Last