The Calendar hole will go live in approximately 8 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 237th ertz1ertz 924 84 330ms 13 Sep 2024 237th Grabnukebomb 924 84 351ms 13 Sep 2024 237th Shanethegamer 🇺🇸 924 84 365ms 9 Apr 2025 237th HumanoidCPU 924 84 392ms 10 Apr 2025 237th annaproxy 924 84 371ms 11 Apr 2025 237th Re-Adventures 🇮🇳 924 84 376ms 15 Apr 2025 237th janbehrens 🇩🇪 924 84 372ms 17 Apr 2025 248th sean-niemann 🇺🇸 923 54 127ms 6 Aug 2024 248th Steffan153 🇫🇮 923 54 126ms 6 Aug 2024 248th lukegustafson 🇺🇸 923 54 116ms 7 Aug 2024 248th pardouin 🇫🇷 923 54 125ms 8 Aug 2024 248th Lydxn 🇨🇦 923 54 121ms 9 Aug 2024 248th JayXon 🇺🇸 923 54 130ms 9 Aug 2024 254th h3ra993huskp 🇯🇵 923 90 440ms 23 days ago 255th KasperKivimaeki 🇫🇮 923 103 237ms 12 days ago 256th ovs-code 🇩🇪 922 60 4ms 9 Oct 2023 256th GrayJoKing 🇦🇺 922 60 4ms 11 Oct 2023 256th Lydxn 🇨🇦 922 60 5ms 11 Oct 2023 256th GolfingSuccess 🇬🇷 922 60 4ms 16 Nov 2023 256th Steffan153 🇫🇮 922 60 5ms 28 Jan 2024 256th JayXon 🇺🇸 922 60 5ms 29 Jan 2024 256th rucin93 🇵🇱 922 60 5ms 10 Jul 2024 256th sean-niemann 🇺🇸 922 60 5ms 10 Jul 2024 264th Steffan153 🇫🇮 922 67 37ms 19 Aug 2024 264th JayXon 🇺🇸 922 67 37ms 19 Aug 2024 266th JayXon 🇺🇸 921 73 4ms 12 hours ago 267th sisyphus-ppcg 🇦🇺 920 65 106ms 4 days ago 267th ovs-code 🇩🇪 920 65 123ms 4 days ago 269th Lydxn 🇨🇦 920 90 125ms 6 May 2022 270th sisyphus-ppcg 🇦🇺 919 50 2,414ms 31 Jan 2023 270th saito-ta 🇯🇵 919 50 759ms 12 Dec 2024 272nd uiamn 919 58 11ms 6 Sep 2022 272nd 5quiwyrm 919 58 10ms 29 Sep 2022 272nd alasdair-greenland 919 58 10ms 13 Jan 2023 272nd kirjavascript 919 58 10ms 4 Aug 2025 272nd Posandu 919 58 10ms 26 Aug 2025 272nd mrxz 🇳🇱 919 58 11ms 3 Sep 2025 278th Herbert00709 🇵🇱 919 92 85ms 17 Nov 2023 278th 4QT0R 919 92 60ms 23 Nov 2023 278th ovs-code 🇩🇪 919 92 76ms 3 Jun 2024 281st primo-ppcg 🇹🇭 917 24 153ms 10 Dec 2022 282nd btnlq 917 59 6ms 6 Nov 2022 282nd DialFrost 🇸🇬 917 59 7ms 8 hours ago 284th JayXon 🇺🇸 917 69 552ms 5 Apr 2023 284th Lydxn 🇨🇦 917 69 549ms 9 Apr 2023 286th nwellnhof 🇩🇪 916 51 43ms 4 May 2022 286th primo-ppcg 🇹🇭 916 51 41ms 6 May 2022 286th janlelis 916 51 44ms 10 May 2022 286th Natanaelel 🇸🇪 916 51 58ms 2 Jun 2022 290th Irratix 🇳🇱 916 61 42ms 7 May 2022 290th TFeld00 🇩🇰 916 61 24ms 17 May 2022 290th hallvabo 🇳🇴 916 61 20ms 4 Sep 2022 290th DialFrost 🇸🇬 916 61 23ms 19 Dec 2022 290th anter69 🇭🇺 916 61 19ms 19 Dec 2022 290th Alex-x90 🇺🇸 916 61 18ms 27 Dec 2022 290th commandblockguy 🇺🇸 916 61 19ms 22 Aug 2023 290th fgrosshans 🇫🇷 916 61 18ms 22 Jul 2024 290th duckyluuk 🇳🇱 916 61 20ms 15 Aug 2024 290th rucin93 🇵🇱 916 61 17ms 31 May 2025 290th katss2 916 61 18ms 17 Aug 2025 290th snoozingnewt 🇨🇦 916 61 23ms 17 days ago 302nd MichalMarsalek 🇨🇿 916 71 143ms 5 May 2022 302nd Lydxn 🇨🇦 916 71 174ms 7 May 2022 302nd GrayJoKing 🇦🇺 916 71 122ms 8 May 2022 302nd JayXon 🇺🇸 916 71 121ms 8 May 2022 302nd Steffan153 🇫🇮 916 71 133ms 9 Mar 2023 302nd Shanethegamer 🇺🇸 916 71 131ms 15 May 2023 302nd MeWhenI 🇻🇦 916 71 128ms 8 Aug 2023 302nd sean-niemann 🇺🇸 916 71 127ms 9 Jan 2025 310th Steffan153 🇫🇮 915 76 11ms 15 May 2023 310th primo-ppcg 🇹🇭 915 76 17ms 15 May 2023 310th Lydxn 🇨🇦 915 76 8ms 22 May 2023 310th GrayJoKing 🇦🇺 915 76 13ms 24 Aug 2023 314th edsrzf 🇳🇿 914 54 817ms 13 Sep 2025 314th CaedenHarper 🇨🇦 914 54 826ms 27 Sep 2025 314th sean-niemann 🇺🇸 914 54 833ms 27 Sep 2025 314th albanian-laundromat 914 54 859ms 14 Nov 2025 314th xsot 🇸🇬 914 54 873ms 15 Nov 2025 319th xnor-gate 914 63 187ms 20 Jan 2025 320th arctouch-cristiannevianna 913 85 341ms 3 Apr 2023 First Prev 241–320 of 3,475 Next Last