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 317th xsot 🇸🇬 914 54 873ms 15 Nov 2025 322nd xnor-gate 914 63 187ms 20 Jan 2025 323rd arctouch-cristiannevianna 913 85 341ms 3 Apr 2023 323rd Widgitty 913 85 319ms 1 Sep 2023 323rd tomtheisen 🇺🇸 913 85 396ms 10 Apr 2025 326th kmathis22 913 91 548ms 20 Nov 2025 327th primo-ppcg 🇹🇭 912 61 6ms 6 May 2022 327th sisyphus-ppcg 🇦🇺 912 61 9ms 14 Jul 2022 329th Steffan153 🇫🇮 912 71 4ms 10 Dec 2022 329th synt7x 🇺🇸 912 71 4ms 7 Jul 2025 331st pardouin 🇫🇷 912 72 3,684ms 21 May 2025 332nd edsrzf 🇳🇿 912 78 19ms 16 Aug 2025 333rd Lydxn 🇨🇦 911 70 96ms 7 May 2022 333rd JayXon 🇺🇸 911 70 96ms 7 May 2022 335th Steffan153 🇫🇮 911 71 98ms 14 Oct 2022 335th Shanethegamer 🇺🇸 911 71 100ms 15 Oct 2022 335th stefangimmillaro 911 71 100ms 16 Oct 2022 335th MeWhenI 🇻🇦 911 71 100ms 16 Oct 2022 339th annaproxy 911 78 111ms 13 Jan 2023 339th IanUtley 911 78 114ms 12 Nov 2023 339th GrayJoKing 🇦🇺 911 78 79ms 28 Nov 2023 342nd Shanethegamer 🇺🇸 911 86 390ms 15 May 2023 342nd JayXon 🇺🇸 911 86 508ms 15 May 2023 342nd Steffan153 🇫🇮 911 86 389ms 16 May 2023 342nd Lydxn 🇨🇦 911 86 465ms 16 May 2023 342nd GrayJoKing 🇦🇺 911 86 400ms 11 Aug 2023 342nd sean-niemann 🇺🇸 911 86 436ms 11 Jul 2024 348th Bubbler-4 910 33 2,528ms 6 May 2022 348th rak1507 🇬🇧 910 33 108ms 8 May 2022 348th ngn 🇧🇬 910 33 25ms 11 May 2022 348th zacjl 910 33 32ms 3 Jun 2025 348th GrayJoKing 🇦🇺 910 33 13ms 4 Jun 2025 348th HPWiz 🇳🇿 910 33 9ms 16 Nov 2025 354th andersk 🇺🇸 910 91 124ms 25 Oct 2022 354th Super-Pizza 🇨🇦 910 91 124ms 4 Dec 2022 354th klixel 🇨🇦 910 91 125ms 20 May 2023 354th lynn 910 91 122ms 6 Jul 2024 354th edsrzf 🇳🇿 910 91 125ms 29 Nov 2024 354th DialFrost 🇸🇬 910 91 136ms 7 Apr 2025 360th Lydxn 🇨🇦 909 47 303ms 5 May 2022 361st JayXon 🇺🇸 909 53 375ms 17 Aug 2024 362nd Lydxn 🇨🇦 909 81 39ms 1 Apr 2023 363rd tailorspy 909 93 84ms 27 May 2024 363rd sean-niemann 🇺🇸 909 93 81ms 9 Jun 2025 363rd KasperKivimaeki 🇫🇮 909 93 56ms 26 Oct 2025 366th nai62 908 68 7ms 27 Aug 2022 367th ovs-code 🇩🇪 908 75 78ms 12 Sep 2024 367th Kacarott 🇦🇺 908 75 62ms 13 Sep 2024 369th Shanethegamer 🇺🇸 907 61 3ms 9 Oct 2023 369th edsrzf 🇳🇿 907 61 3ms 4 Jul 2025 371st GrayJoKing 🇦🇺 907 74 64ms 1 Nov 2023 372nd lynn 907 78 1,300ms 5 May 2022 373rd sean-niemann 🇺🇸 906 66 108ms 29 May 2025 374th GrayJoKing 🇦🇺 905 71 321ms 10 Aug 2023 375th primo-ppcg 🇹🇭 905 93 30ms 7 May 2022 375th AlephSquirrel 905 93 26ms 21 Jan 2023 375th kg583 🇺🇸 905 93 29ms 26 Dec 2024 375th CLOStrophobic 🇮🇹 905 93 30ms 17 Jan 2025 375th edsrzf 🇳🇿 905 93 30ms 3 Jul 2025 380th JayXon 🇺🇸 905 105 246ms 4 Oct 2025 381st KrausRaus 🇺🇸 903 59 10ms 4 May 2022 381st voytxt 🇨🇿 903 59 9ms 4 May 2022 381st KingSkyrock 🇺🇸 903 59 9ms 18 May 2022 381st ZakkkkAttackkkk 🇵🇭 903 59 9ms 14 Jul 2022 381st aksyristos 903 59 11ms 28 Oct 2022 381st nstearns96 🇬🇧 903 59 10ms 28 Nov 2022 381st janbehrens 🇩🇪 903 59 9ms 17 May 2023 381st Shanethegamer 🇺🇸 903 59 10ms 25 May 2023 381st Maznek 903 59 10ms 26 Jun 2023 381st SpiritAxolotl 🇺🇸 903 59 10ms 20 Mar 2024 381st Andrey-Plotnikov 903 59 9ms 19 May 2024 381st emgordon154 903 59 10ms 5 Aug 2024 381st duckyluuk 🇳🇱 903 59 10ms 3 Oct 2024 381st lifthrasiir 🇰🇷 903 59 10ms 23 Nov 2024 381st fuzzylojik-golf 🇺🇸 903 59 10ms 1 Jun 2025 381st acollett89 903 59 10ms 17 Jun 2025 381st iczelia 🇩🇪 903 59 10ms 23 Sep 2025 398th edsrzf 🇳🇿 903 72 160ms 3 Jul 2025 399th Shanethegamer 🇺🇸 903 77 13ms 15 May 2023 400th marshallward 🇺🇸 903 83 41ms 10 May 2022 First Prev 321–400 of 3,502 Next Last