The Calendar hole will go live in approximately 7 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 321st arctouch-cristiannevianna 913 85 341ms 3 Apr 2023 321st Widgitty 913 85 319ms 1 Sep 2023 321st tomtheisen 🇺🇸 913 85 396ms 10 Apr 2025 324th kmathis22 913 91 548ms 20 Nov 2025 325th primo-ppcg 🇹🇭 912 61 7ms 6 May 2022 325th sisyphus-ppcg 🇦🇺 912 61 12ms 14 Jul 2022 327th pardouin 🇫🇷 912 72 3,684ms 21 May 2025 328th edsrzf 🇳🇿 912 78 19ms 16 Aug 2025 329th Lydxn 🇨🇦 911 70 96ms 7 May 2022 329th JayXon 🇺🇸 911 70 96ms 7 May 2022 331st Steffan153 🇫🇮 911 71 98ms 14 Oct 2022 331st Shanethegamer 🇺🇸 911 71 100ms 15 Oct 2022 331st stefangimmillaro 911 71 100ms 16 Oct 2022 331st MeWhenI 🇻🇦 911 71 100ms 16 Oct 2022 335th annaproxy 911 78 111ms 13 Jan 2023 335th IanUtley 911 78 114ms 12 Nov 2023 335th GrayJoKing 🇦🇺 911 78 79ms 28 Nov 2023 338th Shanethegamer 🇺🇸 911 86 390ms 15 May 2023 338th JayXon 🇺🇸 911 86 508ms 15 May 2023 338th Steffan153 🇫🇮 911 86 389ms 16 May 2023 338th Lydxn 🇨🇦 911 86 465ms 16 May 2023 338th GrayJoKing 🇦🇺 911 86 400ms 11 Aug 2023 338th sean-niemann 🇺🇸 911 86 436ms 11 Jul 2024 344th Bubbler-4 910 33 2,528ms 6 May 2022 344th rak1507 🇬🇧 910 33 108ms 8 May 2022 344th ngn 🇧🇬 910 33 25ms 11 May 2022 344th zacjl 910 33 32ms 3 Jun 2025 344th GrayJoKing 🇦🇺 910 33 13ms 4 Jun 2025 344th HPWiz 🇳🇿 910 33 9ms 16 Nov 2025 350th andersk 🇺🇸 910 91 124ms 25 Oct 2022 350th Super-Pizza 🇨🇦 910 91 124ms 4 Dec 2022 350th klixel 🇨🇦 910 91 125ms 20 May 2023 350th lynn 910 91 122ms 6 Jul 2024 350th edsrzf 🇳🇿 910 91 125ms 29 Nov 2024 350th DialFrost 🇸🇬 910 91 136ms 7 Apr 2025 356th Lydxn 🇨🇦 909 47 283ms 5 May 2022 357th JayXon 🇺🇸 909 53 375ms 17 Aug 2024 358th GrayJoKing 🇦🇺 909 74 4ms 30 hours ago 359th Lydxn 🇨🇦 909 81 39ms 1 Apr 2023 360th tailorspy 909 93 55ms 27 May 2024 360th sean-niemann 🇺🇸 909 93 53ms 9 Jun 2025 360th KasperKivimaeki 🇫🇮 909 93 56ms 26 Oct 2025 363rd nai62 908 68 7ms 27 Aug 2022 364th ovs-code 🇩🇪 908 75 78ms 12 Sep 2024 364th Kacarott 🇦🇺 908 75 62ms 13 Sep 2024 366th Shanethegamer 🇺🇸 907 61 3ms 9 Oct 2023 366th edsrzf 🇳🇿 907 61 3ms 4 Jul 2025 368th GrayJoKing 🇦🇺 907 74 64ms 1 Nov 2023 369th lynn 907 78 1,300ms 5 May 2022 370th sean-niemann 🇺🇸 906 66 108ms 29 May 2025 371st GrayJoKing 🇦🇺 905 71 321ms 10 Aug 2023 372nd primo-ppcg 🇹🇭 905 93 30ms 7 May 2022 372nd AlephSquirrel 905 93 26ms 21 Jan 2023 372nd kg583 🇺🇸 905 93 29ms 26 Dec 2024 372nd CLOStrophobic 🇮🇹 905 93 30ms 17 Jan 2025 372nd edsrzf 🇳🇿 905 93 30ms 3 Jul 2025 377th JayXon 🇺🇸 905 105 246ms 4 Oct 2025 378th KrausRaus 🇺🇸 904 59 10ms 4 May 2022 378th voytxt 🇨🇿 904 59 9ms 4 May 2022 378th KingSkyrock 🇺🇸 904 59 9ms 18 May 2022 378th ZakkkkAttackkkk 🇵🇭 904 59 9ms 14 Jul 2022 378th aksyristos 904 59 11ms 28 Oct 2022 378th nstearns96 🇬🇧 904 59 10ms 28 Nov 2022 378th janbehrens 🇩🇪 904 59 9ms 17 May 2023 378th Shanethegamer 🇺🇸 904 59 10ms 25 May 2023 378th Maznek 904 59 10ms 26 Jun 2023 378th SpiritAxolotl 🇺🇸 904 59 10ms 20 Mar 2024 378th Andrey-Plotnikov 904 59 9ms 19 May 2024 378th emgordon154 904 59 10ms 5 Aug 2024 378th duckyluuk 🇳🇱 904 59 10ms 3 Oct 2024 378th lifthrasiir 🇰🇷 904 59 10ms 23 Nov 2024 378th fuzzylojik-golf 🇺🇸 904 59 10ms 1 Jun 2025 378th acollett89 904 59 10ms 17 Jun 2025 378th iczelia 🇩🇪 904 59 10ms 23 Sep 2025 395th edsrzf 🇳🇿 903 72 160ms 3 Jul 2025 396th Shanethegamer 🇺🇸 903 77 13ms 15 May 2023 397th marshallward 🇺🇸 903 83 41ms 10 May 2022 398th Betuaredead 902 60 5ms 5 Jan 2023 398th Yewzir 🇧🇪 902 60 5ms 12 Feb 2023 398th Steffan153 🇫🇮 902 60 5ms 23 Feb 2023 First Prev 321–400 of 3,478 Next Last