The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them 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 Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions 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 Multitap Input 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 Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> ALGOL 68 ArkScript 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 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> ALGOL 68 ArkScript 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 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily 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 Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions 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 Multitap Input 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 Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Bytes Time Submitted 321st martinnorling 🇸🇪 840 75 24ms 5 May 2022 321st Trunksistor 🇫🇷 840 75 24ms 9 May 2022 321st bbakersmith 840 75 22ms 28 Jun 2022 321st bsoyka 🇺🇸 840 75 19ms 16 Jul 2022 321st P-Quentin 🇫🇷 840 75 21ms 3 Aug 2022 321st julienlamoureux78 840 75 20ms 12 Aug 2022 321st dzshn 840 75 24ms 16 Aug 2022 321st NerdyMcNerd42 840 75 20ms 20 Aug 2022 321st destofr 840 75 18ms 25 Aug 2022 321st vishwathg 840 75 49ms 10 Oct 2022 321st nkoppel 840 75 19ms 19 Oct 2022 321st AZ9tumas 840 75 20ms 23 Oct 2022 321st EthanGrant1 840 75 24ms 7 Nov 2022 321st Omega65536 🇩🇪 840 75 19ms 24 Nov 2022 321st b10011 🇫🇮 840 75 24ms 3 Jan 2023 321st 4ndyJ 🇬🇧 840 75 23ms 3 Jan 2023 321st randolchance 840 75 21ms 8 Jan 2023 321st LeeCamp 840 75 20ms 12 Jan 2023 321st hellwue 840 75 20ms 15 Feb 2023 321st nandanjp 840 75 20ms 29 Mar 2023 321st kaptsanovb 840 75 24ms 20 Apr 2023 321st galloj 🇨🇿 840 75 18ms 20 May 2023 321st jhu04 840 75 19ms 23 Jun 2023 321st HelloYuiYui 840 75 18ms 1 Nov 2023 321st tobyLovick 840 75 26ms 10 Nov 2023 321st VictorStenvers 🇳🇱 840 75 22ms 13 Nov 2023 321st RZ781 840 75 27ms 19 Nov 2023 321st mikehanus 840 75 26ms 21 Nov 2023 321st 1231234md5 🇨🇳 840 75 20ms 14 Dec 2023 321st Hebelub 840 75 23ms 6 Jan 2024 321st minhtrancccp 840 75 25ms 11 Jan 2024 321st 123mjb 840 75 22ms 25 Jan 2024 321st jbjd 840 75 23ms 25 Feb 2024 321st gabe-gallegos 840 75 19ms 2 May 2024 321st kejcao 🇨🇦 840 75 25ms 11 May 2024 321st f-tucker 840 75 22ms 24 May 2024 321st Florian-Mt 840 75 19ms 22 Jul 2024 321st codingisgreatbutiamnot 840 75 21ms 9 Aug 2024 321st Terobero 840 75 32ms 23 Aug 2024 321st abhishekg999 840 75 49ms 17 Sep 2024 321st RedzGoose 🇦🇺 840 75 22ms 7 Oct 2024 321st Clay-Goodling 840 75 24ms 8 Oct 2024 321st JunkIce 840 75 24ms 5 Mar 2025 321st jiji7879 840 75 24ms 20 Jun 2025 321st faragocsaba 840 75 24ms 22 Jun 2025 321st bknower 840 75 19ms 30 Jun 2025 321st clayboll99 840 75 23ms 14 Jul 2025 321st Nikinator2704 840 75 18ms 1 Nov 2025 321st mmoffitt 840 75 26ms 19 Nov 2025 321st AdrienHache 🇫🇷 840 75 19ms 20 Dec 2025 321st enigma 840 75 32ms 21 Dec 2025 321st jesuscbm 840 75 19ms 27 days ago 321st ASampsonMu31 840 75 51ms 12 days ago 374th guilhem-roy 🇫🇷 829 76 24ms 5 May 2022 374th NewDefectus 🇮🇱 829 76 22ms 6 May 2022 374th CuboidRaptor 🇨🇦 829 76 23ms 25 May 2022 374th TheSmilingTurtle 829 76 26ms 5 Jun 2022 374th Romain-1 🇫🇷 829 76 19ms 8 Jun 2022 374th jhpaques 🇫🇷 829 76 23ms 30 Jul 2022 374th chriscianfarani 829 76 25ms 10 Aug 2022 374th eshilo-draper 829 76 21ms 13 Sep 2022 374th suwat513 829 76 21ms 22 Sep 2022 374th Jaydosu 829 76 23ms 14 Nov 2022 374th tails618 829 76 27ms 2 Dec 2022 374th KevinLyvers 829 76 20ms 17 Dec 2022 374th nayakrujul 829 76 20ms 3 Jan 2023 374th CheeseCake628 🇳🇴 829 76 23ms 8 Jan 2023 374th CatsAreFluffy 829 76 26ms 18 Feb 2023 374th adamnielson42 🇺🇸 829 76 19ms 1 Mar 2023 374th Schreipfelerer 829 76 27ms 9 Apr 2023 374th hm5822 829 76 27ms 22 Apr 2023 374th celiendonze 🇨🇭 829 76 27ms 5 Jul 2023 374th brochmann 🇸🇪 829 76 21ms 13 Aug 2023 374th Command-Master 829 76 36ms 2 Oct 2023 374th chartung17 829 76 21ms 17 Dec 2023 374th smokestacklightnin 🇺🇸 829 76 26ms 10 Jan 2024 374th NickTheEASDude 🇺🇸 829 76 53ms 26 Jan 2024 374th yuchuehw 829 76 26ms 2 Feb 2024 374th Azearia 829 76 26ms 26 Feb 2024 374th tpasfieldERAU 829 76 22ms 18 May 2024 First Prev 321–400 of 841 Next Last
