12 Days of Christmas
13th
99 Bottles of Beer
8th
Abundant Numbers
9th
Christmas Trees
4th
Cubes
4th
Diamonds
7th
Divisors
21st
Emirp Numbers
7th
Emojify
2nd
Evil Numbers
12th
Fizz Buzz
13th
Happy Numbers
7th
Intersection
5th
Leap Years
16th
Leyland Numbers
4th
Look and Say
6th
Lucky Tickets
4th
Morse Decoder
3rd
Morse Encoder
3rd
Niven Numbers
19th
Odious Numbers
12th
Ordinal Numbers
5th
Pangram Grep
10th
Pascal’s Triangle
36th
Pernicious Numbers
19th
Poker
2nd
Prime Numbers
13th
Recamán
7th
Rock-paper-scissors-Spock-lizard
3rd
Roman to Arabic
17th
Rule 110
5th
Seven Segment
7th
Spelling Numbers
4th
Tongue-twisters
15th
United States
4th