12 Days of Christmas
38th
24 Game
11th
99 Bottles of Beer
25th
Arrows
21st
Card Number Validation
14th
Collatz
31st
Day of Week
25th
Diamonds
28th
Divisors
129th
Farey Sequence
18th
Fizz Buzz
254th
Forsyth–Edwards Notation
11th
ISBN
18th
Kaprekar Numbers
10th
Leap Years
72nd
Niven Numbers
58th
Pernicious Numbers
45th
Rock-paper-scissors-Spock-lizard
10th
Seven Segment
29th
Ten-pin Bowling
8th
Tongue-twisters
21st
π
17th
𝑒
21st