The Calendar hole will go live in approximately 12 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 240th JayXon 🇺🇸 924 70 99ms 17 Oct 2022 242nd roavin 924 84 337ms 23 Jun 2022 242nd tkr-sh 🇰🇵 924 84 318ms 20 Aug 2022 242nd Nickmiste 924 84 326ms 9 Nov 2022 242nd postie77 924 84 323ms 19 May 2023 242nd ertz1ertz 924 84 330ms 13 Sep 2024 242nd Grabnukebomb 924 84 351ms 13 Sep 2024 242nd Shanethegamer 🇺🇸 924 84 365ms 9 Apr 2025 242nd HumanoidCPU 924 84 392ms 10 Apr 2025 242nd annaproxy 924 84 371ms 11 Apr 2025 242nd Re-Adventures 🇮🇳 924 84 376ms 15 Apr 2025 242nd janbehrens 🇩🇪 924 84 372ms 17 Apr 2025 253rd sean-niemann 🇺🇸 923 54 127ms 6 Aug 2024 253rd Steffan153 🇫🇮 923 54 126ms 6 Aug 2024 253rd lukegustafson 🇺🇸 923 54 116ms 7 Aug 2024 253rd pardouin 🇫🇷 923 54 125ms 8 Aug 2024 253rd Lydxn 🇨🇦 923 54 121ms 9 Aug 2024 253rd JayXon 🇺🇸 923 54 130ms 9 Aug 2024 259th h3ra993huskp 🇯🇵 923 90 440ms 19 days ago 260th KasperKivimaeki 🇫🇮 923 103 237ms 8 days ago 261st ovs-code 🇩🇪 922 60 4ms 9 Oct 2023 261st GrayJoKing 🇦🇺 922 60 4ms 11 Oct 2023 261st Lydxn 🇨🇦 922 60 5ms 11 Oct 2023 261st GolfingSuccess 🇬🇷 922 60 4ms 16 Nov 2023 261st Steffan153 🇫🇮 922 60 5ms 28 Jan 2024 261st JayXon 🇺🇸 922 60 5ms 29 Jan 2024 261st rucin93 🇵🇱 922 60 5ms 10 Jul 2024 261st sean-niemann 🇺🇸 922 60 5ms 10 Jul 2024 269th Steffan153 🇫🇮 922 67 37ms 19 Aug 2024 269th JayXon 🇺🇸 922 67 37ms 19 Aug 2024 271st sisyphus-ppcg 🇦🇺 920 65 106ms 10 hours ago 271st ovs-code 🇩🇪 920 65 123ms 50 mins ago 273rd Lydxn 🇨🇦 920 90 125ms 6 May 2022 274th sisyphus-ppcg 🇦🇺 919 50 2,414ms 31 Jan 2023 274th saito-ta 🇯🇵 919 50 759ms 12 Dec 2024 276th uiamn 919 58 11ms 6 Sep 2022 276th 5quiwyrm 919 58 10ms 29 Sep 2022 276th alasdair-greenland 919 58 10ms 13 Jan 2023 276th kirjavascript 919 58 10ms 4 Aug 2025 276th Posandu 919 58 10ms 26 Aug 2025 276th mrxz 🇳🇱 919 58 11ms 3 Sep 2025 282nd Herbert00709 🇵🇱 919 92 85ms 17 Nov 2023 282nd 4QT0R 919 92 60ms 23 Nov 2023 282nd ovs-code 🇩🇪 919 92 76ms 3 Jun 2024 285th primo-ppcg 🇹🇭 917 24 153ms 10 Dec 2022 286th btnlq 917 59 6ms 6 Nov 2022 287th JayXon 🇺🇸 917 69 552ms 5 Apr 2023 287th Lydxn 🇨🇦 917 69 549ms 9 Apr 2023 289th nwellnhof 🇩🇪 916 51 43ms 4 May 2022 289th primo-ppcg 🇹🇭 916 51 41ms 6 May 2022 289th janlelis 916 51 44ms 10 May 2022 289th Natanaelel 🇸🇪 916 51 58ms 2 Jun 2022 293rd Irratix 🇳🇱 916 61 42ms 7 May 2022 293rd TFeld00 🇩🇰 916 61 24ms 17 May 2022 293rd hallvabo 🇳🇴 916 61 20ms 4 Sep 2022 293rd DialFrost 🇸🇬 916 61 23ms 19 Dec 2022 293rd anter69 🇭🇺 916 61 19ms 19 Dec 2022 293rd Alex-x90 🇺🇸 916 61 18ms 27 Dec 2022 293rd commandblockguy 🇺🇸 916 61 19ms 22 Aug 2023 293rd fgrosshans 🇫🇷 916 61 18ms 22 Jul 2024 293rd duckyluuk 🇳🇱 916 61 20ms 15 Aug 2024 293rd rucin93 🇵🇱 916 61 17ms 31 May 2025 293rd katss2 916 61 18ms 17 Aug 2025 293rd snoozingnewt 🇨🇦 916 61 23ms 13 days ago 305th MichalMarsalek 🇨🇿 916 71 143ms 5 May 2022 305th Lydxn 🇨🇦 916 71 174ms 7 May 2022 305th GrayJoKing 🇦🇺 916 71 122ms 8 May 2022 305th JayXon 🇺🇸 916 71 121ms 8 May 2022 305th Steffan153 🇫🇮 916 71 133ms 9 Mar 2023 305th Shanethegamer 🇺🇸 916 71 131ms 15 May 2023 305th MeWhenI 🇻🇦 916 71 128ms 8 Aug 2023 305th sean-niemann 🇺🇸 916 71 127ms 9 Jan 2025 313th Steffan153 🇫🇮 915 76 11ms 15 May 2023 313th primo-ppcg 🇹🇭 915 76 17ms 15 May 2023 313th Lydxn 🇨🇦 915 76 8ms 22 May 2023 313th GrayJoKing 🇦🇺 915 76 13ms 24 Aug 2023 317th edsrzf 🇳🇿 914 54 817ms 13 Sep 2025 317th CaedenHarper 🇨🇦 914 54 826ms 27 Sep 2025 317th sean-niemann 🇺🇸 914 54 833ms 27 Sep 2025 317th albanian-laundromat 914 54 859ms 14 Nov 2025 First Prev 241–320 of 3,502 Next Last