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
All Languages
><>
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
Bytes
Chars
Scoring
Bytes
Chars
Language
All
><>
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
12 Days of Christmas
nwellnhof
💎
433
5 days ago
Quine
edsrzf
65
6 days ago
Emojify
nwellnhof
🥈
141
7 days ago
Zeckendorf Representation
canissimia
💎
213
7 days ago
SI Units
dokutan
1,383
10 days ago
ln 2
klixel
1,003
11 days ago
12 Days of Christmas
dokutan
540
13 days ago
Tongue-twisters
dokutan
342
13 days ago
Sierpiński Triangle
dokutan
177
13 days ago
Polyominoes
nwellnhof
🥈
118
19 days ago
Ordinal Numbers
pardouin
48
23 days ago
Inventory Sequence
dokutan
1,440
23 days ago
Emirp Numbers (Long)
dokutan
851
23 days ago
Cubes
dokutan
685
23 days ago
Diamonds
dokutan
246
23 days ago
Spelling Numbers
dokutan
588
24 days ago
Card Number Validation
nwellnhof
🥈
68
24 days ago
Gijswijt’s Sequence
Mabeloid
3,000
25 days ago
Number Spiral
Mabeloid
311
25 days ago
Prime Numbers
Mabeloid
96
25 days ago
Prime Numbers (Long)
Mabeloid
7,177
25 days ago
Card Number Validation
galloj
112
25 days ago
Pernicious Numbers
Mabeloid
135
25 days ago
Pernicious Numbers (Long)
Mabeloid
24,914
25 days ago
Pascal’s Triangle
Mabeloid
789
25 days ago
Inventory Sequence
Mabeloid
3,623
25 days ago
Recamán
Mabeloid
1,147
26 days ago
Van Eck Sequence
Mabeloid
3,555
26 days ago
Cubes
Mabeloid
4,213
26 days ago
Arithmetic Numbers
Mabeloid
45,330
26 days ago
Card Number Validation
retrohun
146
26 days ago
brainfuck
jacobly0
510
27 days ago
Card Number Validation
canissimia
💎
66
1 Oct 2024
Card Number Validation
saito-ta
🥉
74
1 Oct 2024
Card Number Validation
MeWhenI
98
1 Oct 2024
Fractions
MeWhenI
🥉
331
26 Sep 2024
Evil Numbers (Long)
MeWhenI
1,529
26 Sep 2024
Leyland Numbers
MeWhenI
835
26 Sep 2024
DFA Simulator
MeWhenI
180
26 Sep 2024
Fibonacci
MeWhenI
146
26 Sep 2024
Odious Numbers
Mabeloid
99
22 Sep 2024
Odious Numbers (Long)
Mabeloid
2,445
22 Sep 2024
Rule 110
Mabeloid
15,953
22 Sep 2024
Leap Years
Mabeloid
876
22 Sep 2024
Niven Numbers
Mabeloid
124
22 Sep 2024
Niven Numbers (Long)
Mabeloid
8,976
22 Sep 2024
Leyland Numbers
Mabeloid
993
22 Sep 2024
Sierpiński Triangle
Mabeloid
571
22 Sep 2024
Roman to Arabic
retrohun
🥉
111
21 Sep 2024
Niven Numbers
pardouin
85
21 Sep 2024
Kolakoski Sequence
Mabeloid
2,001
21 Sep 2024
Rijndael S-box
Mabeloid
784
21 Sep 2024
Pernicious Numbers
pardouin
🥉
86
21 Sep 2024
Happy Numbers
pardouin
99
21 Sep 2024
Emirp Numbers
pardouin
🥇
125
21 Sep 2024
Prime Numbers
pardouin
🥇
66
21 Sep 2024
Odious Numbers
pardouin
🥇
68
21 Sep 2024
Evil Numbers
pardouin
🥇
66
21 Sep 2024
ln 2
Mabeloid
1,004
20 Sep 2024
Look and Say
Mabeloid
1,299
20 Sep 2024
Lucky Numbers
Mabeloid
5,820
20 Sep 2024
Kolakoski Constant
Mabeloid
1,004
20 Sep 2024
Happy Numbers
Mabeloid
139
20 Sep 2024
Evil Numbers
anter69
95
18 Sep 2024
Fizz Buzz
Mabeloid
513
18 Sep 2024
Foo Fizz Buzz Bar
Mabeloid
6,719
18 Sep 2024
Fibonacci
Mabeloid
165
18 Sep 2024
Happy Numbers (Long)
Mabeloid
695
18 Sep 2024
Abundant Numbers
Mabeloid
209
18 Sep 2024
Abundant Numbers (Long)
Mabeloid
1,210
18 Sep 2024
24 Game
Mabeloid
13,794
18 Sep 2024
Catalan Numbers
Mabeloid
2,972
17 Sep 2024
Collatz
Mabeloid
4,226
17 Sep 2024
Divisors
Mabeloid
1,266
17 Sep 2024
Diamonds
Mabeloid
1,193
17 Sep 2024