The Calendar hole will go live in approximately 8 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 877th snoozingnewt 🇨🇦 845 64 5ms 1 Sep 2024 877th albanian-laundromat 845 64 5ms 22 Sep 2025 883rd lynn 845 96 29ms 11 Jul 2023 884th Shanethegamer 🇺🇸 845 98 119ms 26 Oct 2022 884th emgordon154 845 98 121ms 18 Feb 2025 886th janAkali 🇷🇺 844 77 123ms 12 Feb 2025 887th bschorno 844 92 366ms 12 Oct 2022 887th ChrisTheisen 844 92 339ms 14 Dec 2022 887th kellantech 844 92 363ms 4 Jul 2023 887th Mezzofloat 844 92 377ms 26 Aug 2023 887th Maximizer02 844 92 360ms 1 Oct 2023 887th madeforlosers 844 92 365ms 21 Nov 2024 887th ChromaChroma 844 92 354ms 7 Oct 2025 887th snoozingnewt 🇨🇦 844 92 379ms 8 Oct 2025 895th DialFrost 🇸🇬 843 66 107ms 7 Apr 2025 895th KasperKivimaeki 🇫🇮 843 66 9ms 23 hours ago 897th dokutan 843 93 428ms 27 Sep 2025 898th krcs 🇵🇱 842 53 282ms 9 May 2022 898th ryanlanegit 842 53 301ms 19 Jun 2022 898th sisyphus-ppcg 🇦🇺 842 53 456ms 15 Aug 2022 901st MeWhenI 🇻🇦 842 71 106ms 13 Dec 2022 902nd SirBogman 🇺🇸 842 89 38ms 4 May 2022 903rd error256 841 81 71ms 13 Sep 2024 904th CLOStrophobic 🇮🇹 841 89 42ms 14 Feb 2025 905th kmathis22 841 100 31ms 13 Nov 2025 906th raszpi 🇭🇺 840 77 103ms 1 Sep 2023 907th eshilo-draper 839 75 86ms 6 Sep 2022 907th kmathis22 839 75 79ms 5 Sep 2025 909th sean-niemann 🇺🇸 839 76 107ms 8 Oct 2024 910th beardotpdf 839 99 346ms 11 days ago 911th emplv 🇱🇻 839 124 25ms 31 Oct 2022 912th Codsilla 🇨🇦 838 51 266ms 1 Jul 2022 913th frankgraziano 838 66 4ms 20 Apr 2025 914th Andriamanitra 🇫🇮 838 83 12ms 17 Apr 2023 914th Natanaelel 🇸🇪 838 83 12ms 8 Jul 2023 916th MeWhenI 🇻🇦 838 164 1,639ms 7 Nov 2025 917th ovs-code 🇩🇪 837 85 15ms 11 Dec 2023 918th dokutan 837 88 39ms 9 Jun 2024 919th Steffan153 🇫🇮 837 97 29ms 18 Jan 2023 920th CatsAreFluffy 837 101 54ms 18 Feb 2023 920th annaproxy 837 101 70ms 9 May 2023 920th wojtekmal 837 101 78ms 15 Nov 2023 920th HumanoidCPU 837 101 83ms 6 May 2024 920th eMGeeneer 837 101 449ms 27 Jun 2024 920th bac0id 837 101 77ms 29 Jun 2024 920th michaelmoynihan 837 101 508ms 3 Sep 2025 920th snoozingnewt 🇨🇦 837 101 517ms 6 Oct 2025 928th SirBogman 🇺🇸 835 36 14ms 5 May 2022 928th Natanaelel 🇸🇪 835 36 87ms 15 Jun 2022 928th Steffan153 🇫🇮 835 36 91ms 18 Jan 2023 928th codereport 🇨🇦 835 36 9ms 1 Jun 2024 928th GolfinK 835 36 9ms 21 Nov 2024 928th lifthrasiir 🇰🇷 835 36 10ms 1 Dec 2024 928th GolfingSuccess 🇬🇷 835 36 11ms 20 Mar 2025 935th scpchicken 🇵🇼 835 55 10ms 4 May 2022 935th SirBogman 🇺🇸 835 55 6ms 5 May 2022 935th Shanethegamer 🇺🇸 835 55 6ms 19 May 2023 935th DialFrost 🇸🇬 835 55 10ms 14 Feb 2025 939th ChiefChippy2 835 56 51ms 4 May 2022 939th aksyristos 835 56 42ms 29 Jan 2023 939th anter69 🇭🇺 835 56 38ms 12 Feb 2024 939th 3dm4n 🇫🇮 835 56 38ms 11 Mar 2024 939th lgrandco 835 56 43ms 9 Oct 2024 939th tatzyr 🇯🇵 835 56 43ms 10 Dec 2024 939th D-MOVE 🇵🇭 835 56 49ms 15 days ago 946th inverseLorentz 🇦🇺 835 69 156ms 3 Jun 2024 946th Yewzir 🇧🇪 835 69 118ms 24 Dec 2024 946th CLOStrophobic 🇮🇹 835 69 170ms 28 May 2025 949th p-vf 🇨🇭 835 93 337ms 24 Jun 2022 949th Smetalo 835 93 384ms 25 Aug 2022 949th malworthy 835 93 360ms 19 Aug 2024 952nd moustave 834 67 23ms 7 Nov 2024 953rd Alex-x90 🇺🇸 834 74 2ms 4 Dec 2022 953rd undersquire 834 74 2ms 24 Jun 2023 953rd rdmsr 834 74 2ms 24 Jun 2023 953rd Bmrl7 834 74 2ms 9 Jul 2023 953rd Vinterion 834 74 4ms 6 Nov 2023 953rd namelessiw 834 74 2ms 28 Dec 2023 953rd Jonatan6 🇩🇰 834 74 2ms 15 Mar 2024 953rd Mandrzejy 🇵🇱 834 74 2ms 12 Apr 2024 First Prev 881–960 of 3,475 Next Last