The Calendar hole will go live in approximately 13 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 453rd bricknellj 896 69 17ms 13 days ago 482nd ovs-code 🇩🇪 896 89 438ms 24 Jul 2024 482nd jipsong 🇩🇪 896 89 467ms 7 Apr 2025 484th MichalMarsalek 🇨🇿 895 87 366ms 5 May 2022 484th Kloppermand 🇩🇰 895 87 375ms 7 Oct 2022 484th bwat2 895 87 348ms 6 Apr 2023 487th Shanethegamer 🇺🇸 894 61 5ms 31 Oct 2022 487th MeWhenI 🇻🇦 894 61 5ms 4 Nov 2022 489th JayXon 🇺🇸 894 74 4,306ms 14 Nov 2024 490th oeb25 894 93 120ms 16 May 2022 490th snobee 🇨🇦 894 93 119ms 8 Dec 2022 490th logvp 894 93 120ms 2 Jan 2024 490th elgan65536 894 93 120ms 5 Mar 2024 490th smartiel 894 93 124ms 12 Aug 2024 490th trist224 🇫🇷 894 93 122ms 12 Aug 2024 490th nullie 894 93 119ms 19 Dec 2024 490th lolgeny 894 93 116ms 22 Feb 2025 498th m-tkach 🇺🇦 894 117 25ms 7 May 2022 498th Lydxn 🇨🇦 894 117 26ms 7 May 2022 500th Yewzir 🇧🇪 893 72 92ms 27 days ago 501st GolfingSuccess 🇬🇷 893 95 74ms 5 May 2022 501st Alex-x90 🇺🇸 893 95 57ms 4 Dec 2022 501st Mandrzejy 🇵🇱 893 95 67ms 22 Mar 2024 504th Steffan153 🇫🇮 892 52 7ms 31 Dec 2022 505th DialFrost 🇸🇬 892 56 863ms 1 Sep 2025 506th KatieLG 🇬🇧 892 60 10ms 4 May 2022 506th ScottHamper 892 60 10ms 5 May 2022 506th Re-Adventures 🇮🇳 892 60 10ms 5 May 2022 506th 0x24a537r9 892 60 10ms 29 Jul 2022 506th stefangabos 🇷🇴 892 60 10ms 19 Aug 2022 506th eranws 892 60 10ms 10 Sep 2022 506th GeorgeStechman 🇬🇧 892 60 10ms 26 Sep 2022 506th BloodStormKnight 892 60 10ms 15 Oct 2022 506th dzshn 892 60 10ms 3 Dec 2022 506th biocommando 🇫🇮 892 60 10ms 20 Dec 2022 506th Betuaredead 892 60 9ms 5 Jan 2023 506th piano-miles 892 60 9ms 16 Jan 2023 506th Yewzir 🇧🇪 892 60 10ms 12 Feb 2023 506th shellbertt 🇨🇦 892 60 10ms 26 Feb 2023 506th zakariamouhid 892 60 10ms 20 May 2023 506th raphaelimahorn 892 60 10ms 23 Aug 2023 506th jbt 892 60 9ms 25 Dec 2023 506th olleicua 🇺🇸 892 60 10ms 15 Feb 2024 506th HumanoidCPU 892 60 10ms 3 May 2024 506th dokutan 892 60 10ms 13 Aug 2024 506th LostSyntax21 🇬🇧 892 60 11ms 10 Sep 2024 506th xyangst 892 60 10ms 28 Sep 2024 506th a6166231 🇨🇳 892 60 9ms 15 May 2025 506th Protothor 892 60 10ms 8 Jul 2025 506th SebassNoob 892 60 10ms 5 Aug 2025 506th Yax42 🇫🇷 892 60 10ms 5 Sep 2025 506th levinwinter 892 60 10ms 22 Oct 2025 506th Cube14yt 892 60 10ms 16 Nov 2025 506th gigaprofisi 🇺🇸 892 60 10ms 17 Nov 2025 535th stefangimmillaro 892 71 91ms 2 Oct 2022 535th Steffan153 🇫🇮 892 71 96ms 23 Feb 2023 535th Shanethegamer 🇺🇸 892 71 90ms 16 May 2023 535th sean-niemann 🇺🇸 892 71 89ms 12 Jul 2024 539th RockOfStone 892 73 4ms 20 Oct 2025 540th Lydxn 🇨🇦 892 108 263ms 6 May 2022 540th CaedenHarper 🇨🇦 892 108 308ms 5 Oct 2025 542nd lynn 891 65 283ms 5 May 2022 542nd GrayJoKing 🇦🇺 891 65 250ms 5 May 2022 542nd Sakisan 🇧🇪 891 65 178ms 6 May 2022 542nd JayXon 🇺🇸 891 65 311ms 17 Oct 2022 542nd Steffan153 🇫🇮 891 65 185ms 12 Nov 2022 542nd tobeannouncd 891 65 312ms 25 Apr 2025 542nd sean-niemann 🇺🇸 891 65 168ms 9 Jun 2025 549th GrayJoKing 🇦🇺 891 77 96ms 13 Sep 2024 550th DialFrost 🇸🇬 891 95 29ms 10 Dec 2024 551st canissimia 🇦🇶 891 110 2,640ms 20 Feb 2023 552nd jared-hughes 891 130 23ms 15 Dec 2024 553rd primo-ppcg 🇹🇭 890 52 297ms 5 May 2022 553rd dvargas46 🇺🇸 890 52 92ms 22 Dec 2022 555th canissimia 🇦🇶 890 204 16ms 25 Nov 2023 556th mousetail 🇳🇱 888 41 66ms 29 Aug 2025 557th MeWhenI 🇻🇦 888 53 58ms 1 Jun 2022 557th stefangimmillaro 888 53 56ms 2 Oct 2022 557th Haksell 🇦🇶 888 53 46ms 22 Feb 2023 560th primo-ppcg 🇹🇭 888 85 39ms 14 Jan 2025 First Prev 481–560 of 3,526 Next Last