The Calendar hole will go live in approximately 8 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 601st namelessiw 883 70 20ms 9 Jan 2024 601st mathisfun271 883 70 18ms 13 Feb 2024 601st Just4FunCoder 883 70 20ms 17 Feb 2024 601st ThijsLuttikhuis 883 70 19ms 3 Mar 2024 601st elgan65536 883 70 19ms 5 Mar 2024 601st jtaxen 883 70 18ms 1 Apr 2024 601st HumanoidCPU 883 70 19ms 6 May 2024 601st abc7-12 883 70 18ms 6 May 2024 601st ahmetdemirag 🇨🇾 883 70 18ms 9 Jun 2024 601st FranklinJiaChen 883 70 21ms 4 Jul 2024 601st 5cw 🇺🇸 883 70 18ms 13 Jul 2024 601st CaedenHarper 🇨🇦 883 70 18ms 3 Aug 2024 601st emgordon154 883 70 19ms 5 Aug 2024 601st dokutan 883 70 23ms 9 Aug 2024 601st jatloe 883 70 19ms 26 Aug 2024 601st lgrandco 883 70 19ms 9 Oct 2024 601st snydej 883 70 19ms 21 Nov 2024 601st erikji 883 70 19ms 4 Feb 2025 601st CutSandstone 883 70 19ms 4 Feb 2025 601st albanian-laundromat 883 70 19ms 12 Apr 2025 601st xsot 🇸🇬 883 70 22ms 3 May 2025 601st fuzzylojik-golf 🇺🇸 883 70 19ms 14 Jun 2025 601st smilesformiles3 883 70 19ms 14 Jun 2025 601st KasperKivimaeki 🇫🇮 883 70 19ms 30 Jun 2025 601st adaGrad1 883 70 18ms 10 Aug 2025 601st EthanJantz 883 70 18ms 10 Aug 2025 601st qpwoeirut 883 70 16ms 10 Aug 2025 601st katss2 883 70 19ms 17 Aug 2025 601st intgrah 883 70 18ms 23 Sep 2025 601st ryyyn 🇺🇸 883 70 18ms 29 Oct 2025 601st luuumine 🇫🇷 883 70 18ms 3 Nov 2025 601st Babafaba 883 70 19ms 7 Nov 2025 601st commandblockguy 🇺🇸 883 70 19ms 16 Nov 2025 601st hellopir2 883 70 22ms 23 Nov 2025 601st bzijlema 🇳🇱 883 70 20ms 20 days ago 676th Shanethegamer 🇺🇸 882 51 428ms 15 May 2023 677th GrayJoKing 🇦🇺 882 60 133ms 24 Oct 2024 678th GrayJoKing 🇦🇺 882 84 37ms 19 Jun 2022 678th primo-ppcg 🇹🇭 882 84 36ms 29 Jun 2022 680th Shanethegamer 🇺🇸 881 73 90ms 8 May 2025 680th DialFrost 🇸🇬 881 73 83ms 3 Jun 2025 680th edsrzf 🇳🇿 881 73 98ms 4 Jul 2025 683rd Shanethegamer 🇺🇸 881 142 511ms 27 Mar 2025 683rd DialFrost 🇸🇬 881 142 490ms 28 Mar 2025 683rd emgordon154 881 142 395ms 10 Apr 2025 683rd GolfingSuccess 🇬🇷 881 142 463ms 17 days ago 687th primo-ppcg 🇹🇭 881 193 107ms 14 Aug 2025 688th dokutan 880 62 5ms 28 Apr 2025 689th johnnythedoggie 880 72 91ms 13 May 2022 689th kaascevich 880 72 90ms 8 Jul 2025 691st Shanethegamer 🇺🇸 878 66 172ms 4 May 2022 691st scpchicken 🇵🇼 878 66 254ms 5 May 2022 691st sisyphus-ppcg 🇦🇺 878 66 174ms 6 May 2022 691st Natanaelel 🇸🇪 878 66 144ms 15 Jun 2022 691st Z-snails 878 66 254ms 27 Feb 2023 691st Jeremy-Stafford 878 66 258ms 27 Feb 2023 691st alomiF 878 66 293ms 1 Sep 2023 691st btnlq 878 66 145ms 17 Oct 2023 699th DialFrost 🇸🇬 878 86 40ms 24 Oct 2024 699th stefangimmillaro 878 86 42ms 14 Jan 2025 701st emgordon154 878 97 128ms 19 days ago 702nd JayXon 🇺🇸 878 158 1,772ms 14 Sep 2025 703rd c0d3-4-F00d 🇩🇪 877 61 10ms 6 May 2022 703rd jackkav 877 61 10ms 26 Jun 2022 703rd TechNolaByte 877 61 10ms 6 Jul 2022 703rd Heathcorp 🇦🇺 877 61 9ms 17 Jul 2022 703rd C0de5mith 🇺🇸 877 61 11ms 3 Aug 2022 703rd sebipopa 🇷🇴 877 61 10ms 18 Aug 2022 703rd moikaturns 🇬🇧 877 61 9ms 25 Sep 2022 703rd FlorianCassayre 🇫🇷 877 61 10ms 27 Sep 2022 703rd Mazn3k 877 61 10ms 1 Feb 2023 703rd tvcv901 877 61 10ms 22 Mar 2023 703rd unfinishedprogram 877 61 10ms 19 Jul 2023 703rd snoozingnewt 🇨🇦 877 61 10ms 23 Sep 2023 703rd funnyboy-roks 877 61 10ms 9 May 2024 703rd bac0id 877 61 10ms 29 Jun 2024 703rd madex 🇩🇪 877 61 10ms 9 Jul 2024 703rd FortuiteMan 🇫🇷 877 61 9ms 10 Oct 2024 703rd RobertHoeh 877 61 13ms 5 Apr 2025 703rd LvLError 877 61 10ms 29 May 2025 First Prev 641–720 of 3,499 Next Last