The Calendar hole will go live in approximately 7 days. Why not try and solve it ahead of time?
Prime Numbers in C# 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 1st JayXon 🇺🇸 1,000 62 398ms 13 Jun 2023 1st Lydxn 🇨🇦 1,000 62 344ms 1 Jul 2023 1st AdrienHache 🇫🇷 1,000 62 387ms 16 hours ago 4th stefangimmillaro 984 63 390ms 12 Jun 2023 4th namelessiw 984 63 378ms 9 Aug 2024 4th fuzzylojik-golf 🇺🇸 984 63 384ms 31 Jul 2025 7th nwellnhof 🇩🇪 969 64 314ms 21 Dec 2021 7th btnlq 969 64 341ms 10 Mar 2023 7th MeWhenI 🇻🇦 969 64 338ms 26 Jul 2023 7th sean-niemann 🇺🇸 969 64 357ms 23 Dec 2024 7th WalrusesAreAwesome 969 64 378ms 11 Jan 2025 7th prplz 🇦🇺 969 64 343ms 23 Jan 2025 7th Yax42 🇫🇷 969 64 350ms 1 Aug 2025 7th KasperKivimaeki 🇫🇮 969 64 352ms 2 days ago 15th Attero 🇸🇪 954 65 317ms 21 Nov 2021 15th billings7 🇬🇧 954 65 321ms 21 Nov 2021 15th KatieLG 🇬🇧 954 65 384ms 21 Nov 2021 15th primo-ppcg 🇹🇭 954 65 321ms 21 Nov 2021 15th tomtheisen 🇺🇸 954 65 344ms 21 Nov 2021 15th roavin 954 65 311ms 29 Jun 2022 15th annaproxy 954 65 340ms 19 May 2023 15th b-illy 🇬🇧 954 65 349ms 21 Jan 2025 15th albanian-laundromat 954 65 367ms 16 hours ago 24th ScottHamper 939 66 308ms 21 Nov 2021 24th Shanethegamer 🇺🇸 939 66 308ms 28 Dec 2021 24th Yewzir 🇧🇪 939 66 319ms 8 May 2023 24th janbehrens 🇩🇪 939 66 312ms 27 Nov 2023 24th SirBogman 🇺🇸 939 66 308ms 3 Jan 2024 29th KrausRaus 🇺🇸 912 68 329ms 26 Jun 2023 30th Gaddy 🇫🇷 899 69 330ms 1 Jun 2022 30th postie77 899 69 310ms 18 Apr 2023 32nd Irratix 🇳🇱 886 70 323ms 13 Dec 2021 32nd Ripick 886 70 314ms 18 Jul 2022 32nd CatsAreFluffy 886 70 330ms 28 Nov 2022 35th sultan 873 71 325ms 2 Apr 2024 36th tkr-sh 🇰🇵 861 72 307ms 4 May 2022 36th ChrisTheisen 861 72 328ms 19 Dec 2022 36th mathb0y512 861 72 316ms 8 Feb 2023 39th LS2021 849 73 319ms 24 Nov 2023 39th dokutan 849 73 356ms 14 Jul 2025 41st Meowsan91 🇨🇿 827 75 333ms 21 Nov 2021 41st SmartK8 🇨🇿 827 75 315ms 13 Nov 2022 43rd pan4ever 816 76 315ms 21 Nov 2021 43rd hamhub7 816 76 323ms 26 Aug 2022 43rd Matgc04 816 76 322ms 23 Feb 2024 43rd Squimbletin 816 76 349ms 22 Apr 2025 47th CarsonChr 🇺🇸 795 78 318ms 7 Apr 2024 48th hyvyys 785 79 320ms 21 Nov 2021 49th aliakseikalosha 775 80 383ms 21 Nov 2021 49th oren0 775 80 319ms 21 Nov 2021 49th adlerzei 775 80 347ms 5 May 2022 49th arctouch-sergeymetlov 775 80 322ms 21 Jun 2023 49th ElysiaVesper 775 80 317ms 19 Nov 2023 49th Re-Adventures 🇮🇳 775 80 372ms 15 Apr 2025 55th tdkkdt 🇷🇺 765 81 322ms 21 Nov 2021 55th tomh1012 765 81 385ms 21 Nov 2021 55th MLPdiscord 765 81 326ms 10 Jan 2022 55th josephdwalker 765 81 321ms 14 Nov 2023 59th ILMTitan 756 82 346ms 21 Nov 2021 59th Romain-1 🇫🇷 756 82 370ms 1 Jun 2022 59th arctouch-cristiannevianna 756 82 358ms 23 May 2023 59th kkoenig 756 82 318ms 25 Dec 2023 59th FreyLuis 756 82 347ms 17 Jan 2024 59th michelebastione 🇮🇹 756 82 384ms 27 Aug 2025 65th castur1 747 83 322ms 3 Feb 2022 66th JDiLenarda 🇫🇷 738 84 325ms 21 Nov 2021 66th najs91 738 84 319ms 21 Nov 2021 66th bac0id 738 84 320ms 22 Sep 2023 66th epic-programmer-guy 738 84 317ms 19 Dec 2023 66th QzLP2P 738 84 310ms 29 Mar 2024 66th malworthy 738 84 372ms 16 Aug 2024 66th arcpolaris 738 84 365ms 27 Mar 2025 73rd leth4 729 85 344ms 5 Jul 2023 73rd CaedenHarper 🇨🇦 729 85 379ms 17 Oct 2025 73rd Adix-null 🇱🇹 729 85 422ms 10 Nov 2025 76th ericlangedijk 🇸🇮 721 86 337ms 16 Mar 2022 76th Betuaredead 721 86 309ms 4 Jan 2023 76th HumanoidCPU 721 86 316ms 1 Apr 2024 79th pallbo 713 87 319ms 21 Nov 2021 79th Florian-Mt 713 87 354ms 14 Jul 2024 1–80 of 143 Next Last