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 721st MeWhenI 🇻🇦 866 85 41ms 27 Jun 2022 721st Shanethegamer 🇺🇸 866 85 38ms 15 May 2023 721st albanian-laundromat 866 85 40ms 25 Aug 2025 724th 123mjb 866 96 356ms 20 Nov 2025 724th noescareno 866 96 406ms 21 Nov 2025 726th DialFrost 🇸🇬 864 64 5ms 10 Jul 2024 727th emplv 🇱🇻 864 110 296ms 5 May 2022 727th Shanethegamer 🇺🇸 864 110 261ms 21 Nov 2023 727th edsrzf 🇳🇿 864 110 258ms 28 Nov 2024 727th targrik 864 110 267ms 30 Jun 2025 731st emgordon154 864 159 1,744ms 46 hours ago 732nd deadp4nda 🇩🇪 863 90 372ms 26 Apr 2024 732nd 123mjb 863 90 339ms 23 Jun 2025 732nd michelebastione 🇮🇹 863 90 384ms 24 Aug 2025 732nd razvandmtr 🇷🇴 863 90 368ms 6 Nov 2025 736th TylerBloom 863 96 115ms 22 Mar 2024 737th Shanethegamer 🇺🇸 863 97 100ms 15 Apr 2025 737th GolfingSuccess 🇬🇷 863 97 111ms 28 Nov 2025 737th DialFrost 🇸🇬 863 97 94ms 25 days ago 740th shellbertt 🇨🇦 863 98 63ms 9 May 2022 740th iakolzin 863 98 61ms 26 May 2022 740th Betuaredead 863 98 61ms 5 Jan 2023 740th oceko 863 98 63ms 19 Feb 2024 740th dokutan 863 98 61ms 17 Mar 2024 740th cuzdav 863 98 60ms 4 May 2025 740th timhaj 🇸🇮 863 98 61ms 12 Sep 2025 740th Yax42 🇫🇷 863 98 60ms 4 Oct 2025 748th Steffan153 🇫🇮 862 82 1,287ms 23 Feb 2023 749th steffan-polygolf 861 73 87ms 23 Feb 2023 749th MWI-polygolf 861 73 83ms 6 Dec 2023 749th HumanoidCPU 861 73 81ms 7 May 2024 752nd Steffan153 🇫🇮 861 78 80ms 4 Feb 2023 753rd GrayJoKing 🇦🇺 860 56 411ms 15 Jan 2024 753rd AlephSquirrel 860 56 426ms 21 Jan 2024 755th Setvizan 860 62 10ms 12 Jan 2023 755th GreenBeansAgainstVeganism 860 62 10ms 13 Jan 2023 755th arctouch-cristiannevianna 860 62 10ms 3 Apr 2023 755th Corxldyphik 860 62 10ms 11 Apr 2023 755th Blockyheadman 860 62 10ms 1 Nov 2023 755th ollyspooner 860 62 10ms 22 Nov 2023 755th itserasmus 860 62 10ms 25 Jan 2024 755th Jacob385 860 62 10ms 13 Mar 2024 755th junkondo-jp 860 62 11ms 30 Jun 2024 755th ShiraJoseph 🇺🇸 860 62 9ms 1 Mar 2025 755th tomh1012 860 62 9ms 23 days ago 766th yzhs 🇩🇪 860 65 19ms 16 Jun 2022 766th rollershutter 860 65 20ms 9 Sep 2022 766th bac0id 860 65 20ms 26 Sep 2023 766th robin-scragg 860 65 23ms 8 Jun 2025 766th RaBa21 🇭🇺 860 65 29ms 11 Jul 2025 766th TransformLikeATensor 860 65 20ms 17 Oct 2025 772nd Andriamanitra 🇫🇮 860 67 144ms 26 Apr 2023 773rd MeWhenI 🇻🇦 859 81 8ms 23 May 2023 774th MeWhenI 🇻🇦 859 145 526ms 28 Mar 2025 775th ulucs 858 35 9ms 8 May 2022 775th bstrat 858 35 9ms 6 Jun 2024 775th wh3n3v3r 🇨🇿 858 35 8ms 18 Nov 2024 778th JRaspass 🇬🇧 858 41 348ms 4 May 2022 778th SirBogman 🇺🇸 858 41 225ms 4 May 2022 778th Natanaelel 🇸🇪 858 41 326ms 4 May 2022 781st 5quiwyrm 858 52 249ms 4 Sep 2022 781st MeWhenI 🇻🇦 858 52 280ms 28 Jan 2023 781st Feniske 🇫🇷 858 52 280ms 7 Nov 2023 781st dcgjb 858 52 297ms 29 Jan 2024 781st JPRuskin 🇬🇧 858 52 278ms 7 Apr 2025 781st IISResetMe 858 52 267ms 7 Apr 2025 781st Ripick 858 52 251ms 1 Jun 2025 788th Yewzir 🇧🇪 858 160 2,399ms 14 Nov 2025 789th jared-hughes 857 72 2ms 6 Jul 2022 789th Steffan153 🇫🇮 857 72 2ms 3 Jan 2023 789th MeWhenI 🇻🇦 857 72 3ms 7 May 2023 789th ListeriaM 857 72 2ms 22 Aug 2023 789th larcherMTT 857 72 2ms 5 Oct 2024 789th snyderek 🇺🇸 857 72 3ms 19 Feb 2025 789th 5quiwyrm 857 72 2ms 29 Jun 2025 789th TeodorDyakov 🇧🇬 857 72 3ms 8 Jul 2025 789th xiaoyiming123 857 72 2ms 12 Jul 2025 798th Liibe 857 97 391ms 25 Sep 2025 798th Schmitt-Very-Cool 857 97 435ms 26 Sep 2025 800th typeswitch-dev 🇵🇹 856 75 5ms 22 Jul 2023 First Prev 721–800 of 3,482 Next Last