The
Kaprekar Numbers
hole will go live in
2 days
. Why not try and solve it ahead of time?
Recent Solutions
Golfers
Solutions
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
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
Intersection
Inventory Sequence
ISBN
Jacobi Symbol
Kolakoski Constant
Kolakoski Sequence
Leap Years
Levenshtein Distance
Leyland Numbers
ln 2
Look and Say
Lucky Numbers
Lucky Tickets
Mahjong
Maze
Medal Tally
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
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
Rule 110
Seven Segment
SI Units
Sierpiński Triangle
Smith Numbers
Spelling Numbers
Star Wars Opening Crawl
Sudoku
Sudoku (Fill-in)
Ten-pin Bowling
Time Distance
Tongue-twisters
Transpose Sentence
United States
Vampire Numbers
Van Eck Sequence
Zeckendorf Representation
Zodiac Signs
γ
λ
π
τ
φ
√2
𝑒
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brainfuck
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><>
Assembly
AWK
Bash
BASIC
Berry
brainfuck
C
C#
C++
Civet
Clojure
COBOL
Coconut
Crystal
D
Dart
Elixir
F#
Factor
Forth
Fortran
Go
GolfScript
Haskell
Hexagony
J
Janet
Java
JavaScript
jq
Julia
K
Kotlin
Lisp
Lua
Nim
OCaml
Pascal
Perl
PHP
PowerShell
Prolog
Python
R
Raku
Rockstar
Ruby
Rust
Scheme
sed
SQL
Swift
Tcl
TeX
V
VimL
Wren
Zig
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
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
Intersection
Inventory Sequence
ISBN
Jacobi Symbol
Kolakoski Constant
Kolakoski Sequence
Leap Years
Levenshtein Distance
Leyland Numbers
ln 2
Look and Say
Lucky Numbers
Lucky Tickets
Mahjong
Maze
Medal Tally
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
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
Rule 110
Seven Segment
SI Units
Sierpiński Triangle
Smith Numbers
Spelling Numbers
Star Wars Opening Crawl
Sudoku
Sudoku (Fill-in)
Ten-pin Bowling
Time Distance
Tongue-twisters
Transpose Sentence
United States
Vampire Numbers
Van Eck Sequence
Zeckendorf Representation
Zodiac Signs
γ
λ
π
τ
φ
√2
𝑒
Hole
Golfer
Bytes
Submitted
λ
duckyluuk
💎
393
2 days ago
Rijndael S-box
dokutan
811
10 days ago
Ascending Primes
dokutan
527
11 days ago
12 Days of Christmas
dokutan
523
12 days ago
Fizz Buzz
aliakseikalosha
269
12 days ago
Fizz Buzz
CaedenHarper
133
12 days ago
Recamán
dokutan
885
13 days ago
Cubes
dokutan
1,126
13 days ago
Sierpiński Triangle
dokutan
274
13 days ago
Polyominoes
dokutan
🥈
1,546
13 days ago
Gijswijt’s Sequence
dokutan
275
13 days ago
Happy Numbers
dokutan
143
15 days ago
Number Spiral
dokutan
314
15 days ago
Forsyth–Edwards Notation
dokutan
759
15 days ago
Kolakoski Sequence
dokutan
439
15 days ago
Fizz Buzz
snoozingnewt
133
18 days ago
Fractions
duckyluuk
110
21 days ago
Gijswijt’s Sequence
Mabeloid
3,004
25 days ago
Number Spiral
Mabeloid
314
25 days ago
Prime Numbers
Mabeloid
100
25 days ago
Prime Numbers (Long)
Mabeloid
7,181
25 days ago
Pernicious Numbers
Mabeloid
139
25 days ago
Pernicious Numbers (Long)
Mabeloid
24,918
25 days ago
Pascal’s Triangle
Mabeloid
793
25 days ago
Inventory Sequence
Mabeloid
3,627
25 days ago
Van Eck Sequence
KatieLG
3,559
25 days ago
Vampire Numbers
KatieLG
1,230
25 days ago
Tongue-twisters
KatieLG
541
25 days ago
Smith Numbers
KatieLG
2,204
25 days ago
Sierpiński Triangle
KatieLG
574
25 days ago
Rule 110
KatieLG
15,956
25 days ago
Rijndael S-box
KatieLG
788
25 days ago
Recamán
KatieLG
1,151
25 days ago
Proximity Grid
KatieLG
🥉
3,940
25 days ago
Prime Numbers (Long)
KatieLG
7,181
25 days ago
Prime Numbers
KatieLG
100
25 days ago
Polyominoes
KatieLG
4,834
25 days ago
Pernicious Numbers (Long)
KatieLG
24,918
25 days ago
Pernicious Numbers
KatieLG
139
25 days ago
Pascal’s Triangle
KatieLG
793
25 days ago
Odious Numbers (Long)
KatieLG
2,449
25 days ago
Odious Numbers
KatieLG
103
25 days ago
Number Spiral
KatieLG
314
25 days ago
Niven Numbers (Long)
KatieLG
8,980
25 days ago
Niven Numbers
KatieLG
128
25 days ago
N Queens
KatieLG
1,398
25 days ago
Lucky Numbers
KatieLG
5,824
25 days ago
Look and Say
KatieLG
1,303
25 days ago
Leyland Numbers
KatieLG
997
25 days ago
Leap Years
KatieLG
880
25 days ago
Inventory Sequence
KatieLG
3,627
25 days ago
Hexdump
KatieLG
🥉
6,310
25 days ago
Happy Numbers (Long)
KatieLG
699
25 days ago
Happy Numbers
KatieLG
143
25 days ago
Gijswijt’s Sequence
KatieLG
3,004
25 days ago
Foo Fizz Buzz Bar
KatieLG
6,723
25 days ago
Fizz Buzz
KatieLG
517
25 days ago
Fibonacci
KatieLG
169
25 days ago
Farey Sequence
KatieLG
5,133
25 days ago
Evil Numbers (Long)
KatieLG
2,455
25 days ago
Evil Numbers
KatieLG
99
25 days ago
Emirp Numbers (Long)
KatieLG
1,400
25 days ago
Emirp Numbers
KatieLG
176
25 days ago
Divisors
KatieLG
1,270
25 days ago
Diamonds
KatieLG
1,196
25 days ago
Cubes
KatieLG
4,216
25 days ago
Collatz
KatieLG
4,230
25 days ago
Christmas Trees
KatieLG
604
25 days ago
Catalan Numbers
KatieLG
2,976
25 days ago
Ascending Primes
KatieLG
616
25 days ago
Abundant Numbers (Long)
KatieLG
1,214
25 days ago
Abundant Numbers
KatieLG
213
25 days ago
24 Game
KatieLG
13,798
25 days ago
12 Days of Christmas
KatieLG
2,486
25 days ago
ASCII Table
KatieLG
296
25 days ago