The Calendar hole will go live in approximately 11 days. Why not try and solve it ahead of time?
Collatz in Python 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 720th DrPrettyman 533 107 15ms 5 Jul 2023 720th joseph-w0ng 533 107 14ms 5 Jul 2024 720th EnisEfe0 533 107 24ms 18 May 2025 724th landyrisbad 528 108 20ms 13 Nov 2022 724th cakular 528 108 27ms 17 May 2024 724th glassala 528 108 16ms 25 Oct 2024 724th CarterStroik 528 108 19ms 12 Nov 2025 728th tjefferson401 523 109 27ms 16 Sep 2022 728th ariesmarinus 523 109 17ms 21 Nov 2024 730th profJGermain 518 110 19ms 7 Feb 2024 730th JMMMMC 518 110 20ms 23 Oct 2024 730th jtb0362 518 110 19ms 10 May 2025 733rd sagnik3 509 112 18ms 8 Aug 2022 733rd craftablescience 509 112 17ms 19 Sep 2023 735th kelseychristensen 504 113 19ms 2 Nov 2022 735th ArmsTheLimited 504 113 14ms 1 Jun 2023 737th HunterC14 500 114 26ms 18 Oct 2024 738th jstechman 496 115 20ms 24 Feb 2024 738th dan422442 496 115 19ms 19 Oct 2024 740th keelanfh 491 116 16ms 20 Dec 2023 740th returnitynet 491 116 16ms 27 Jan 2025 740th EthanPatel01000101 491 116 16ms 20 Oct 2025 743rd gioto64 487 117 16ms 8 Dec 2022 743rd WilfredSalmon 487 117 16ms 21 Oct 2023 745th XianchengZ 483 118 18ms 18 Aug 2023 745th brindak2005 483 118 16ms 2 May 2025 747th jmmographer 467 122 22ms 21 Oct 2023 747th RucatJ 467 122 17ms 8 Aug 2025 749th xbxbxb007 463 123 21ms 10 Jan 2024 750th kevinnaviapaiva 442 129 17ms 20 Feb 2025 751st AdrianN001 438 130 17ms 6 Aug 2023 752nd wyatt-the-hump 435 131 15ms 24 Dec 2022 752nd hotmanga 435 131 13ms 20 Oct 2023 752nd Jordynar02 435 131 16ms 3 May 2025 755th Zach10za 429 133 22ms 23 Jan 2024 756th vtilde 425 134 17ms 8 Jan 2024 757th fig-apple 422 135 11ms 24 Jun 2023 758th S-Ruban 416 137 12ms 25 Feb 2023 759th FLOKI0421 410 139 16ms 4 May 2025 759th noahdorsch 410 139 18ms 5 May 2025 761st bartsowka2000 383 149 20ms 10 Jul 2023 762nd KapelMeister 380 150 13ms 5 Sep 2025 763rd sa1640 370 154 15ms 28 Apr 2025 764th arinhyther 368 155 16ms 24 Dec 2022 765th SebbeCaliban 363 157 17ms 11 Apr 2023 766th codefeld 329 173 18ms 5 Mar 2023 767th fl3ur1nestimable 320 178 15ms 24 Oct 2022 768th Laellekoenig 306 186 15ms 7 Nov 2025 769th Siyasia 302 189 16ms 22 Apr 2025 770th kalehika1234 295 193 13ms 24 Apr 2025 771st hannahherbig 294 194 13ms 30 Mar 2023 772nd dahappy1989 278 205 17ms 5 Nov 2023 773rd sahilshresthaa 277 206 13ms 4 May 2025 774th jalbertgordon 275 207 13ms 24 Oct 2023 775th AidanWalter 273 209 14ms 3 Jan 2025 776th sayloren 263 217 19ms 5 Mar 2023 776th AshayP123 263 217 17ms 1 May 2025 778th rubenguajardount 253 225 21ms 4 May 2025 779th amritm55 250 228 14ms 1 Apr 2025 780th clarkatunt19 249 229 21ms 3 May 2025 781st jac1107 248 230 13ms 4 May 2025 781st rcs0252 248 230 15ms 4 May 2025 783rd apurbapokharel 244 234 21ms 3 Apr 2025 784th wlopez44 236 242 13ms 29 Apr 2025 784th sakshiPatel2602 236 242 14ms 3 May 2025 786th Zok030 235 243 14ms 1 Apr 2025 786th Josemnz 235 243 14ms 28 Apr 2025 788th tophy6 232 246 14ms 1 Apr 2025 788th LyndaS317 232 246 14ms 14 Apr 2025 790th letdank 231 247 14ms 1 Apr 2025 790th AdamGonzo1254 231 247 13ms 3 May 2025 792nd shawncrabtree 226 252 17ms 5 Jul 2025 793rd punkroczombie 224 254 16ms 4 May 2025 794th Abulsamad 200 285 15ms 5 May 2025 795th aidnrox 188 303 13ms 2 May 2025 796th OffSecVik 188 304 15ms 25 Feb 2023 797th Hailee100 182 314 14ms 1 Apr 2025 798th lightediand 🇬🇧 179 319 13ms 14 Dec 2022 799th chaamsak 177 322 14ms 1 May 2025 800th joshuamkite 174 328 15ms 15 Aug 2023 First Prev 721–800 of 811 Next Last