The Calendar hole will go live in approximately 7 days. Why not try and solve it ahead of time?
Collatz in Python in bytes. 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 Bytes Time Submitted 632nd arjunarya1 685 92 16ms 28 Aug 2025 632nd TJK-S 685 92 18ms 10 Oct 2025 643rd Bananapants22 677 93 28ms 4 Sep 2022 643rd jaxmattfair 🇺🇸 677 93 19ms 10 Jan 2023 643rd cingulataluke 677 93 19ms 27 Aug 2023 643rd fenix-bear 677 93 19ms 18 Nov 2023 643rd epic-programmer-guy 677 93 23ms 22 Dec 2023 643rd brimstonetrader 677 93 22ms 18 Nov 2024 649th atazzam 🇺🇸 670 94 17ms 18 May 2022 649th rohangpta 670 94 16ms 8 Aug 2022 649th shinylego 670 94 18ms 14 Sep 2022 649th sgaltair 670 94 20ms 4 Nov 2022 649th TotoAJ 670 94 19ms 15 Dec 2023 649th Gusic06 670 94 18ms 6 May 2024 649th kyleyarwood 670 94 20ms 6 Oct 2024 649th jj0786-cell 670 94 19ms 1 Apr 2025 649th griffinschreiber 670 94 19ms 1 Apr 2025 649th o800 670 94 17ms 17 Nov 2025 659th felixcroc 663 95 18ms 30 Mar 2023 659th Pyro569 663 95 19ms 4 Jul 2023 659th rm-rf-innocence 663 95 19ms 19 Dec 2023 659th Bit125 663 95 19ms 30 Jan 2024 659th aalec 663 95 20ms 25 Apr 2024 659th strogor 663 95 19ms 13 Jun 2025 659th cthierfelder 🇲🇨 663 95 19ms 17 Jul 2025 659th ThomasDelepine 663 95 24ms 29 Oct 2025 667th karhuthebear 656 96 24ms 9 May 2022 667th qwjhvbxi 656 96 19ms 6 Feb 2024 667th alfonsoalves 656 96 18ms 21 Jul 2024 667th jeff-re 656 96 15ms 1 Apr 2025 671st a-penton 649 97 15ms 22 Sep 2022 671st jrbud 649 97 18ms 6 Jan 2024 671st befoster 649 97 23ms 22 Feb 2024 671st joshua-el-samalouti 🇩🇪 649 97 22ms 26 May 2024 671st luca1339 649 97 18ms 10 Jun 2024 676th lukemalek 643 98 15ms 10 Oct 2022 676th UltimateGuy0987 643 98 20ms 14 Oct 2022 676th TheLazySquid 643 98 21ms 20 Dec 2022 676th StronkCheese 🇺🇸 643 98 19ms 13 Mar 2023 676th Anthony-Williams-06 643 98 29ms 17 Oct 2023 676th abcdhhhh 643 98 17ms 27 Aug 2024 676th OSYCh314 🇦🇺 643 98 24ms 16 Nov 2024 676th cole-wilson 643 98 19ms 9 Dec 2024 676th Akilles1 643 98 21ms 15 May 2025 676th Hyperoplex145 643 98 18ms 11 Nov 2025 686th LukeRichardson-dev 636 99 15ms 12 May 2022 686th Tagfox 636 99 18ms 18 Jul 2022 686th gabrielsqw 636 99 23ms 24 Oct 2023 686th sciencedjinn 636 99 16ms 8 Nov 2024 686th MrNiknoc 636 99 18ms 15 Jun 2025 691st OppositeShark 630 100 18ms 19 Jul 2022 691st NOS4A5I 630 100 17ms 10 Jan 2023 691st lomarbrick 630 100 17ms 16 May 2023 691st karlaacastro44 630 100 19ms 5 May 2025 695th markus-rekdal 624 101 24ms 10 May 2022 695th fraserli 🇦🇺 624 101 25ms 2 May 2023 695th FCORMERAIS 624 101 17ms 6 Mar 2024 695th yhm138 624 101 13ms 16 Feb 2025 695th MinecraftFan69420 624 101 21ms 31 Oct 2025 700th PogLop 🇨🇿 618 102 19ms 31 Oct 2022 700th AndersH3 🇸🇪 618 102 14ms 17 May 2023 700th JulieGermainUNT 618 102 20ms 2 Apr 2025 700th NicoBliss 618 102 22ms 16 Nov 2025 704th enbyte 612 103 19ms 20 Dec 2022 704th rajlath 612 103 21ms 7 Jan 2023 704th mnurzia 612 103 15ms 12 Oct 2023 704th sqrteipi 612 103 19ms 2 Apr 2024 704th calum12345 612 103 19ms 26 Mar 2025 704th SectorCorruptor 612 103 24ms 14 Aug 2025 710th winigo3 606 104 23ms 8 Aug 2022 710th zt14427 606 104 19ms 30 Apr 2023 710th IoLimmer 606 104 19ms 24 Jul 2024 713th LordSir101 600 105 17ms 19 Jul 2022 713th tmanternach 600 105 19ms 24 Nov 2022 713th weber-hge 600 105 15ms 13 Jun 2023 713th Eugen-str 600 105 19ms 24 Oct 2023 717th ms-tingliang 594 106 14ms 5 Aug 2022 717th achilleasr 594 106 18ms 7 Nov 2022 717th OleBrumm 594 106 19ms 8 Jan 2023 717th AbhilashaTandon 594 106 23ms 19 Sep 2023 First Prev 641–720 of 813 Next Last
