The Calendar hole will go live in approximately 13 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 478th Steffan153 🇫🇮 892 50 408ms 9 Aug 2024 482nd Lydxn 🇨🇦 892 72 353ms 16 Jul 2023 483rd edsrzf 🇳🇿 892 78 11ms 26 Oct 2024 483rd kg583 🇺🇸 892 78 12ms 25 Sep 2025 485th MichalMarsalek 🇨🇿 892 87 366ms 5 May 2022 485th Kloppermand 🇩🇰 892 87 375ms 7 Oct 2022 485th bwat2 892 87 348ms 6 Apr 2023 488th GrayJoKing 🇦🇺 892 91 29ms 19 Jan 2023 489th oeb25 891 93 120ms 16 May 2022 489th snobee 🇨🇦 891 93 119ms 8 Dec 2022 489th logvp 891 93 120ms 2 Jan 2024 489th elgan65536 891 93 120ms 5 Mar 2024 489th smartiel 891 93 124ms 12 Aug 2024 489th trist224 🇫🇷 891 93 122ms 12 Aug 2024 489th nullie 891 93 119ms 19 Dec 2024 489th lolgeny 891 93 116ms 22 Feb 2025 497th p-zubieta 890 48 316ms 6 Mar 2024 498th Ripick 890 73 133ms 8 May 2023 499th Steffan153 🇫🇮 890 80 24ms 11 Dec 2023 500th GolfingSuccess 🇬🇷 890 95 74ms 5 May 2022 500th Alex-x90 🇺🇸 890 95 57ms 4 Dec 2022 500th Mandrzejy 🇵🇱 890 95 67ms 22 Mar 2024 503rd m-tkach 🇺🇦 890 117 25ms 7 May 2022 503rd Lydxn 🇨🇦 890 117 26ms 7 May 2022 505th Steffan153 🇫🇮 889 80 26ms 15 Nov 2022 505th error256 889 80 115ms 8 Apr 2025 507th KatieLG 🇬🇧 888 60 10ms 4 May 2022 507th ScottHamper 888 60 10ms 5 May 2022 507th Re-Adventures 🇮🇳 888 60 10ms 5 May 2022 507th 0x24a537r9 888 60 10ms 29 Jul 2022 507th stefangabos 🇷🇴 888 60 10ms 19 Aug 2022 507th eranws 888 60 10ms 10 Sep 2022 507th GeorgeStechman 🇬🇧 888 60 10ms 26 Sep 2022 507th BloodStormKnight 888 60 10ms 15 Oct 2022 507th dzshn 888 60 10ms 3 Dec 2022 507th biocommando 🇫🇮 888 60 10ms 20 Dec 2022 507th Betuaredead 888 60 9ms 5 Jan 2023 507th piano-miles 888 60 9ms 16 Jan 2023 507th Yewzir 🇧🇪 888 60 10ms 12 Feb 2023 507th shellbertt 🇨🇦 888 60 10ms 26 Feb 2023 507th zakariamouhid 888 60 10ms 20 May 2023 507th raphaelimahorn 888 60 10ms 23 Aug 2023 507th jbt 888 60 9ms 25 Dec 2023 507th olleicua 🇺🇸 888 60 10ms 15 Feb 2024 507th HumanoidCPU 888 60 10ms 3 May 2024 507th dokutan 888 60 10ms 13 Aug 2024 507th LostSyntax21 🇬🇧 888 60 11ms 10 Sep 2024 507th xyangst 888 60 10ms 28 Sep 2024 507th a6166231 🇨🇳 888 60 9ms 15 May 2025 507th Protothor 888 60 10ms 8 Jul 2025 507th SebassNoob 888 60 10ms 5 Aug 2025 507th Yax42 🇫🇷 888 60 10ms 5 Sep 2025 507th levinwinter 888 60 10ms 22 Oct 2025 507th Cube14yt 888 60 10ms 16 Nov 2025 507th gigaprofisi 🇺🇸 888 60 10ms 17 Nov 2025 536th Lydxn 🇨🇦 888 107 263ms 6 May 2022 536th CaedenHarper 🇨🇦 888 107 308ms 5 Oct 2025 538th Shanethegamer 🇺🇸 887 61 5ms 31 Oct 2022 538th MeWhenI 🇻🇦 887 61 5ms 4 Nov 2022 540th P-Quentin 🇫🇷 887 63 18ms 3 Aug 2022 540th kaptsanovb 887 63 28ms 20 Apr 2023 540th fkantelberg 887 63 20ms 14 Jul 2023 540th VictorStenvers 🇳🇱 887 63 22ms 13 Nov 2023 540th 1231234md5 🇨🇳 887 63 18ms 14 Dec 2023 540th f-tucker 887 63 23ms 6 Feb 2024 540th JunkIce 887 63 23ms 24 Nov 2024 540th Kowalskiexe 🇵🇱 887 63 19ms 19 Apr 2025 540th 123mjb 887 63 23ms 2 Jun 2025 540th DrakeSeteraO 887 63 52ms 24 Oct 2025 550th RockOfStone 887 73 4ms 20 Oct 2025 551st JayXon 🇺🇸 887 74 4,306ms 14 Nov 2024 552nd jared-hughes 887 130 23ms 15 Dec 2024 553rd canissimia 🇦🇶 887 204 16ms 25 Nov 2023 554th lynn 886 65 283ms 5 May 2022 554th GrayJoKing 🇦🇺 886 65 250ms 5 May 2022 554th Sakisan 🇧🇪 886 65 178ms 6 May 2022 554th JayXon 🇺🇸 886 65 311ms 17 Oct 2022 554th Steffan153 🇫🇮 886 65 185ms 12 Nov 2022 554th tobeannouncd 886 65 312ms 25 Apr 2025 554th sean-niemann 🇺🇸 886 65 168ms 9 Jun 2025 First Prev 481–560 of 3,501 Next Last