The Calendar hole will go live in approximately 7 days. Why not try and solve it ahead of time?
Pernicious Numbers (Long) in all languages 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 881st msbranicky 678 76 4,249ms 6 Jan 2025 882nd AlephSquirrel 678 97 6ms 5 Aug 2024 883rd angel-p57 🇯🇵 678 215 291ms 11 Dec 2023 884th MeWhenI 🇻🇦 678 245 448ms 19 Apr 2025 885th CatsAreFluffy 677 57 55ms 31 Jan 2023 886th epic-programmer-guy 677 70 589ms 15 Apr 2024 886th Stockoh 🇫🇷 677 70 565ms 24 Jun 2024 888th lacrosse 675 61 50ms 25 days ago 889th CedricGebistorf 675 75 24ms 4 May 2023 889th namelessiw 675 75 26ms 11 Jan 2024 891st emgordon154 674 87 34ms 19 Mar 2025 892nd gjoacorp 🇬🇧 672 109 62ms 4 Aug 2025 893rd helbling 🇨🇭 670 66 11ms 5 Apr 2024 894th Steffan153 🇫🇮 668 71 5ms 20 Nov 2022 895th jacksonhenry3 666 76 23ms 2 Dec 2022 895th Irratix 🇳🇱 666 76 23ms 31 Jan 2023 895th NoahBolohan 🇨🇦 666 76 27ms 8 Feb 2023 895th Andrey2001 666 76 23ms 15 days ago 899th MeWhenI 🇻🇦 666 79 95ms 7 Aug 2023 900th namcartoon06 666 110 59ms 15 Jul 2023 901st MeWhenI 🇻🇦 666 171 1,690ms 7 Nov 2025 902nd snoozingnewt 🇨🇦 665 48 169ms 9 Oct 2025 903rd Yewzir 🇧🇪 665 81 5ms 12 Feb 2024 903rd dokutan 665 81 6ms 23 Mar 2024 905th SirBogman 🇺🇸 661 51 903ms 22 Nov 2022 905th janbehrens 🇩🇪 661 51 1,065ms 27 Nov 2022 907th snoozingnewt 🇨🇦 661 71 8ms 9 Oct 2025 908th Steffan153 🇫🇮 661 251 53ms 2 Aug 2023 909th Codsilla 🇨🇦 660 63 323ms 3 Nov 2023 910th fuzzylojik-golf 🇺🇸 660 67 41ms 9 Jul 2025 910th snoozingnewt 🇨🇦 660 67 16ms 9 Oct 2025 912th dokutan 660 70 9ms 19 Nov 2025 913th msbranicky 658 80 79ms 10 Sep 2023 914th jakobkordez 🇸🇮 657 77 2,248ms 20 Nov 2022 915th SirBogman 🇺🇸 656 253 79ms 22 Nov 2022 916th dokutan 655 98 395ms 21 days ago 917th albanian-laundromat 655 192 536ms 20 Oct 2025 918th BREMAUCY 🇫🇷 654 63 35ms 15 Apr 2024 918th TheZwierzLF 🇵🇱 654 63 43ms 3 days ago 920th aksyristos 654 112 61ms 23 Jan 2023 921st MeWhenI 🇻🇦 654 121 14ms 9 Apr 2024 922nd stefangimmillaro 652 86 105ms 20 Nov 2022 923rd MeWhenI 🇻🇦 652 105 122ms 9 Apr 2024 924th MeWhenI 🇻🇦 651 71 8ms 10 Oct 2023 925th MeWhenI 🇻🇦 651 72 7ms 9 Apr 2024 926th Maznek 650 68 12ms 3 Jul 2023 927th akamayu-ouo 🇹🇼 649 37 3ms 30 Jul 2024 928th Europe2048 649 78 32ms 4 Dec 2024 929th emgordon154 649 83 5ms 20 Mar 2025 929th iczelia 🇩🇪 649 83 4ms 5 Nov 2025 931st snoozingnewt 🇨🇦 649 94 128ms 9 Oct 2025 932nd MeWhenI 🇻🇦 648 52 1,052ms 12 May 2023 933rd HumanoidCPU 646 108 441ms 8 Nov 2025 934th GolfingSuccess 🇬🇷 645 195 489ms 19 Jan 2025 935th aksyristos 643 64 48ms 2 Feb 2023 936th albanian-laundromat 643 96 45ms 22 Aug 2025 937th Betuaredead 643 114 1,423ms 8 Jan 2023 938th MeWhenI 🇻🇦 642 92 45ms 14 Feb 2025 938th AlephSquirrel 642 92 48ms 21 Mar 2025 940th NickTheEASDude 🇺🇸 641 69 12ms 1 May 2024 941st sean-niemann 🇺🇸 641 74 6ms 4 Apr 2023 942nd MeWhenI 🇻🇦 641 89 128ms 27 Jul 2024 943rd namelessiw 640 74 390ms 5 Mar 2024 944th Shanethegamer 🇺🇸 640 121 31ms 31 Mar 2025 945th inventshah 640 155 3,614ms 23 Mar 2023 945th retrohun 640 155 154ms 27 Sep 2025 947th Yewzir 🇧🇪 637 67 788ms 15 Nov 2025 948th dokutan 637 88 102ms 2 May 2024 948th snoozingnewt 🇨🇦 637 88 103ms 9 Oct 2025 950th retrohun 637 115 62ms 28 Dec 2022 951st dokutan 637 179 1,654ms 2 Nov 2025 952nd retrohun 634 85 4ms 28 Dec 2022 952nd elgan65536 634 85 4ms 15 Apr 2024 952nd Yax42 🇫🇷 634 85 4ms 10 Oct 2025 955th Jacob385 634 110 452ms 28 Oct 2025 956th olleicua 🇺🇸 633 65 59ms 3 Feb 2024 957th snoozingnewt 🇨🇦 633 72 136ms 23 Oct 2025 958th 051 🇸🇬 633 80 20ms 26 Dec 2023 959th UnderKoen 🇳🇱 633 125 551ms 20 Apr 2023 960th janbehrens 🇩🇪 632 76 221ms 20 Nov 2022 First Prev 881–960 of 1,820 Next Last