The Calendar hole will go live in approximately 10 days. Why not try and solve it ahead of time?
Fibonacci 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 159th najs91 850 60 389ms 21 Nov 2021 159th yzhs 🇩🇪 850 60 379ms 21 Nov 2021 159th joharasmus 🇸🇪 850 60 362ms 19 Jul 2022 159th JaroPolhosDev 850 60 349ms 13 Sep 2023 159th GarethSpring 850 60 360ms 19 Sep 2023 159th mqtze 850 60 355ms 21 Sep 2023 159th puddnova 850 60 378ms 22 Oct 2024 159th michelebastione 🇮🇹 850 60 360ms 13 Aug 2025 169th PatrickKocken 836 61 371ms 21 Nov 2021 169th TeDeMos 836 61 355ms 21 Nov 2021 169th castur1 836 61 375ms 27 Jan 2022 169th centrolutions 836 61 346ms 24 Nov 2022 169th dorschmeister 836 61 366ms 19 May 2023 169th fkantelberg 836 61 348ms 15 Jul 2023 169th josephdwalker 836 61 380ms 14 Nov 2023 169th epic-programmer-guy 836 61 339ms 25 Dec 2023 169th codewrite 🇬🇧 836 61 388ms 19 Apr 2025 169th Alex-Huggett 🇬🇧 836 61 357ms 13 Sep 2025 179th jahakari 823 62 361ms 21 Nov 2021 179th MichalMarsalek 🇨🇿 823 62 353ms 29 Nov 2021 179th TheRealOhead 🇺🇸 823 62 361ms 25 Nov 2022 179th Mezzofloat 823 62 346ms 24 Aug 2023 179th nyoshe 823 62 358ms 10 Oct 2023 179th hippopotam00sehead 🇨🇦 823 62 352ms 11 Sep 2024 179th Stockoh 🇫🇷 823 62 374ms 4 Nov 2024 179th desecaw13 823 62 331ms 24 Jan 2025 187th ILMTitan 810 63 347ms 21 Nov 2021 187th Domicnt 810 63 356ms 1 Jan 2022 187th CedricGebistorf 810 63 360ms 3 Feb 2022 187th ChrisTheisen 810 63 361ms 13 Dec 2022 187th TimJackMaster 810 63 370ms 25 Jan 2023 187th gazle 810 63 355ms 25 Apr 2024 193rd muztanger 797 64 345ms 21 Nov 2021 193rd Xwilarg 🇫🇷 797 64 358ms 21 Nov 2021 193rd Ripick 797 64 381ms 30 Apr 2023 193rd usernamethatisnttaken 797 64 376ms 6 Sep 2023 193rd Mikey-Beep 🇬🇧 797 64 371ms 24 Jul 2025 198th Andre3582 785 65 408ms 21 Nov 2021 198th enbyte 785 65 366ms 21 Nov 2021 198th MLPdiscord 785 65 369ms 6 Jan 2022 198th Nickmiste 785 65 343ms 13 Nov 2022 198th mqyhlkahu 785 65 350ms 10 Sep 2023 198th trinityy-7 785 65 373ms 6 Mar 2024 198th msbranicky 785 65 350ms 3 Jul 2024 205th aaronze 🇦🇺 773 66 365ms 21 Nov 2021 205th elephantpanda 773 66 352ms 26 Aug 2022 205th eshilo-draper 773 66 354ms 5 Oct 2022 205th heanyang1 773 66 368ms 22 Apr 2025 205th jacekwladzinski 773 66 349ms 2 Oct 2025 205th dpethes 773 66 367ms 10 days ago 211th TheMickeyMouse 761 67 333ms 21 Nov 2021 211th aDwarfNamedUrist 761 67 349ms 21 Nov 2022 211th glatzert 761 67 371ms 12 May 2023 211th Sciman101 761 67 366ms 15 May 2023 211th eiburns 761 67 351ms 7 Sep 2023 211th rollershutter 761 67 327ms 29 Jan 2025 211th kevinnaviapaiva 761 67 320ms 19 Feb 2025 218th jcheritat 750 68 367ms 21 Nov 2021 218th PhonicCanine 750 68 378ms 21 Nov 2021 218th Gpopcorn 750 68 344ms 31 Mar 2022 218th Mortis66666 750 68 346ms 27 May 2022 218th 104210 750 68 354ms 12 Sep 2022 218th Pyro569 750 68 366ms 31 Jul 2023 224th martinnorling 🇸🇪 739 69 357ms 15 Feb 2022 224th PyryL 🇫🇮 739 69 358ms 23 Aug 2024 224th Flix7dev 🇧🇪 739 69 362ms 21 Oct 2025 227th Skellybob56 729 70 368ms 10 Nov 2025 228th Cbrt74088 718 71 384ms 21 Nov 2021 228th MrGraduate 718 71 351ms 21 Nov 2021 228th ccolella-mdc 718 71 360ms 12 Oct 2023 231st charliegaming 708 72 358ms 3 Oct 2023 231st jtaxen 708 72 365ms 30 Mar 2024 231st JarrodCope 708 72 345ms 19 Apr 2024 231st Zach1031 708 72 369ms 15 Nov 2025 235th ericlangedijk 🇸🇮 699 73 346ms 6 Mar 2022 235th xbxbxb007 699 73 352ms 11 Jan 2024 237th ezrillex 689 74 346ms 21 Nov 2021 237th HassanAliKadhem 🇧🇭 689 74 354ms 16 Jan 2022 237th lalkkot 689 74 366ms 29 Apr 2022 237th phpboyscout 689 74 362ms 27 Apr 2023 First Prev 161–240 of 324 Next Last