The Calendar hole will go live in approximately 11 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 873rd prestosilver 🇺🇸 846 73 2ms 17 days ago 882nd DialFrost 🇸🇬 846 87 42ms 5 days ago 883rd Natanaelel 🇸🇪 845 57 417ms 17 Jan 2024 883rd Kacarott 🇦🇺 845 57 394ms 10 Sep 2024 883rd albanian-laundromat 845 57 494ms 7 Oct 2025 886th retrohun 845 64 6ms 6 Nov 2022 886th Re-Adventures 🇮🇳 845 64 5ms 7 Nov 2022 886th stellartux 845 64 5ms 26 Dec 2023 886th bac0id 845 64 5ms 29 Jun 2024 886th snoozingnewt 🇨🇦 845 64 5ms 1 Sep 2024 886th albanian-laundromat 845 64 5ms 22 Sep 2025 892nd lynn 845 96 29ms 11 Jul 2023 893rd Shanethegamer 🇺🇸 845 98 119ms 26 Oct 2022 893rd emgordon154 845 98 121ms 18 Feb 2025 895th jared-hughes 845 100 69ms 20 Jul 2022 895th ZakkkkAttackkkk 🇵🇭 845 100 71ms 10 Aug 2022 895th Walter225 845 100 70ms 25 Jul 2023 898th janAkali 🇷🇺 844 77 123ms 12 Feb 2025 899th bschorno 844 92 366ms 12 Oct 2022 899th ChrisTheisen 844 92 339ms 14 Dec 2022 899th kellantech 844 92 363ms 4 Jul 2023 899th Mezzofloat 844 92 377ms 26 Aug 2023 899th Maximizer02 844 92 360ms 1 Oct 2023 899th madeforlosers 844 92 365ms 21 Nov 2024 899th ChromaChroma 844 92 354ms 7 Oct 2025 899th snoozingnewt 🇨🇦 844 92 379ms 8 Oct 2025 907th DialFrost 🇸🇬 843 66 189ms 7 Apr 2025 908th dokutan 843 93 428ms 27 Sep 2025 909th krcs 🇵🇱 842 53 282ms 9 May 2022 909th ryanlanegit 842 53 301ms 19 Jun 2022 909th sisyphus-ppcg 🇦🇺 842 53 456ms 15 Aug 2022 912th MeWhenI 🇻🇦 842 71 106ms 13 Dec 2022 913th SirBogman 🇺🇸 842 89 38ms 4 May 2022 914th error256 841 81 71ms 13 Sep 2024 915th CLOStrophobic 🇮🇹 841 89 42ms 14 Feb 2025 916th kmathis22 841 100 31ms 13 Nov 2025 917th raszpi 🇭🇺 840 77 103ms 1 Sep 2023 918th eshilo-draper 839 75 86ms 6 Sep 2022 918th kmathis22 839 75 79ms 5 Sep 2025 920th sean-niemann 🇺🇸 839 76 107ms 8 Oct 2024 921st beardotpdf 839 99 346ms 8 days ago 922nd emplv 🇱🇻 839 124 25ms 31 Oct 2022 923rd Codsilla 🇨🇦 838 51 266ms 1 Jul 2022 924th frankgraziano 838 66 4ms 20 Apr 2025 925th Andriamanitra 🇫🇮 838 83 12ms 17 Apr 2023 925th Natanaelel 🇸🇪 838 83 12ms 8 Jul 2023 927th MeWhenI 🇻🇦 838 164 1,639ms 7 Nov 2025 928th ovs-code 🇩🇪 837 85 15ms 11 Dec 2023 929th dokutan 837 88 39ms 9 Jun 2024 930th Steffan153 🇫🇮 837 97 29ms 18 Jan 2023 931st CatsAreFluffy 837 101 54ms 18 Feb 2023 931st annaproxy 837 101 70ms 9 May 2023 931st wojtekmal 837 101 78ms 15 Nov 2023 931st HumanoidCPU 837 101 83ms 6 May 2024 931st eMGeeneer 837 101 449ms 27 Jun 2024 931st bac0id 837 101 77ms 29 Jun 2024 931st michaelmoynihan 837 101 508ms 3 Sep 2025 931st snoozingnewt 🇨🇦 837 101 517ms 6 Oct 2025 939th SirBogman 🇺🇸 835 36 14ms 5 May 2022 939th Natanaelel 🇸🇪 835 36 87ms 15 Jun 2022 939th Steffan153 🇫🇮 835 36 91ms 18 Jan 2023 939th codereport 🇨🇦 835 36 9ms 1 Jun 2024 939th GolfinK 835 36 9ms 21 Nov 2024 939th lifthrasiir 🇰🇷 835 36 10ms 1 Dec 2024 939th GolfingSuccess 🇬🇷 835 36 11ms 20 Mar 2025 946th scpchicken 🇵🇼 835 55 10ms 4 May 2022 946th SirBogman 🇺🇸 835 55 6ms 5 May 2022 946th Shanethegamer 🇺🇸 835 55 6ms 19 May 2023 946th DialFrost 🇸🇬 835 55 10ms 14 Feb 2025 950th ChiefChippy2 835 56 51ms 4 May 2022 950th aksyristos 835 56 42ms 29 Jan 2023 950th anter69 🇭🇺 835 56 38ms 12 Feb 2024 950th 3dm4n 🇫🇮 835 56 38ms 11 Mar 2024 950th lgrandco 835 56 43ms 9 Oct 2024 950th tatzyr 🇯🇵 835 56 43ms 10 Dec 2024 950th D-MOVE 🇵🇭 835 56 49ms 11 days ago 957th inverseLorentz 🇦🇺 835 69 156ms 3 Jun 2024 957th Yewzir 🇧🇪 835 69 118ms 24 Dec 2024 957th CLOStrophobic 🇮🇹 835 69 170ms 28 May 2025 960th p-vf 🇨🇭 835 93 337ms 24 Jun 2022 First Prev 881–960 of 3,505 Next Last