The Calendar hole will go live in approximately 13 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 881st DialFrost 🇸🇬 846 87 42ms 3 days ago 882nd Natanaelel 🇸🇪 845 57 417ms 17 Jan 2024 882nd Kacarott 🇦🇺 845 57 394ms 10 Sep 2024 882nd albanian-laundromat 845 57 494ms 7 Oct 2025 885th retrohun 845 64 6ms 6 Nov 2022 885th Re-Adventures 🇮🇳 845 64 5ms 7 Nov 2022 885th stellartux 845 64 5ms 26 Dec 2023 885th bac0id 845 64 5ms 29 Jun 2024 885th snoozingnewt 🇨🇦 845 64 5ms 1 Sep 2024 885th albanian-laundromat 845 64 5ms 22 Sep 2025 891st lynn 845 96 29ms 11 Jul 2023 892nd Shanethegamer 🇺🇸 845 98 119ms 26 Oct 2022 892nd emgordon154 845 98 121ms 18 Feb 2025 894th jared-hughes 845 100 69ms 20 Jul 2022 894th ZakkkkAttackkkk 🇵🇭 845 100 71ms 10 Aug 2022 894th Walter225 845 100 70ms 25 Jul 2023 897th janAkali 🇷🇺 844 77 123ms 12 Feb 2025 898th DialFrost 🇸🇬 843 66 189ms 7 Apr 2025 899th bschorno 843 92 366ms 12 Oct 2022 899th ChrisTheisen 843 92 339ms 14 Dec 2022 899th kellantech 843 92 363ms 4 Jul 2023 899th Mezzofloat 843 92 377ms 26 Aug 2023 899th Maximizer02 843 92 360ms 1 Oct 2023 899th madeforlosers 843 92 365ms 21 Nov 2024 899th ChromaChroma 843 92 354ms 7 Oct 2025 899th snoozingnewt 🇨🇦 843 92 379ms 8 Oct 2025 907th dokutan 843 93 428ms 27 Sep 2025 908th krcs 🇵🇱 842 53 282ms 9 May 2022 908th ryanlanegit 842 53 301ms 19 Jun 2022 908th sisyphus-ppcg 🇦🇺 842 53 456ms 15 Aug 2022 911th SirBogman 🇺🇸 842 89 38ms 4 May 2022 912th error256 841 81 71ms 13 Sep 2024 913th CLOStrophobic 🇮🇹 841 89 42ms 14 Feb 2025 914th kmathis22 841 100 31ms 13 Nov 2025 915th raszpi 🇭🇺 840 77 103ms 1 Sep 2023 916th eshilo-draper 839 75 86ms 6 Sep 2022 916th kmathis22 839 75 79ms 5 Sep 2025 918th sean-niemann 🇺🇸 839 76 107ms 8 Oct 2024 919th beardotpdf 839 99 346ms 6 days ago 920th emplv 🇱🇻 839 124 25ms 31 Oct 2022 921st Codsilla 🇨🇦 838 51 266ms 1 Jul 2022 922nd frankgraziano 838 66 4ms 20 Apr 2025 923rd Andriamanitra 🇫🇮 838 83 12ms 17 Apr 2023 923rd Natanaelel 🇸🇪 838 83 12ms 8 Jul 2023 925th MeWhenI 🇻🇦 838 164 1,639ms 7 Nov 2025 926th ovs-code 🇩🇪 837 85 15ms 11 Dec 2023 927th dokutan 837 88 39ms 9 Jun 2024 928th Steffan153 🇫🇮 837 97 29ms 18 Jan 2023 929th CatsAreFluffy 837 101 54ms 18 Feb 2023 929th annaproxy 837 101 70ms 9 May 2023 929th wojtekmal 837 101 78ms 15 Nov 2023 929th HumanoidCPU 837 101 83ms 6 May 2024 929th eMGeeneer 837 101 449ms 27 Jun 2024 929th bac0id 837 101 77ms 29 Jun 2024 929th michaelmoynihan 837 101 508ms 3 Sep 2025 929th snoozingnewt 🇨🇦 837 101 517ms 6 Oct 2025 937th SirBogman 🇺🇸 835 36 14ms 5 May 2022 937th Natanaelel 🇸🇪 835 36 87ms 15 Jun 2022 937th Steffan153 🇫🇮 835 36 91ms 18 Jan 2023 937th codereport 🇨🇦 835 36 9ms 1 Jun 2024 937th GolfinK 835 36 9ms 21 Nov 2024 937th lifthrasiir 🇰🇷 835 36 10ms 1 Dec 2024 937th GolfingSuccess 🇬🇷 835 36 11ms 20 Mar 2025 944th scpchicken 🇵🇼 835 55 10ms 4 May 2022 944th SirBogman 🇺🇸 835 55 6ms 5 May 2022 944th Shanethegamer 🇺🇸 835 55 6ms 19 May 2023 944th DialFrost 🇸🇬 835 55 10ms 14 Feb 2025 948th ChiefChippy2 835 56 51ms 4 May 2022 948th aksyristos 835 56 42ms 29 Jan 2023 948th anter69 🇭🇺 835 56 38ms 12 Feb 2024 948th 3dm4n 🇫🇮 835 56 38ms 11 Mar 2024 948th lgrandco 835 56 43ms 9 Oct 2024 948th tatzyr 🇯🇵 835 56 43ms 10 Dec 2024 948th D-MOVE 🇵🇭 835 56 49ms 9 days ago 955th inverseLorentz 🇦🇺 835 69 156ms 3 Jun 2024 955th Yewzir 🇧🇪 835 69 118ms 24 Dec 2024 955th CLOStrophobic 🇮🇹 835 69 170ms 28 May 2025 958th moustave 834 67 23ms 7 Nov 2024 959th Alex-x90 🇺🇸 834 74 2ms 4 Dec 2022 959th undersquire 834 74 2ms 24 Jun 2023 First Prev 881–960 of 3,502 Next Last