99 Bottles of Beer
20th
Abundant Numbers
28th
Christmas Trees
28th
Divisors
31st
Emirp Numbers
21st
Evil Numbers
41st
Fibonacci
73rd
Fizz Buzz
151st
Leap Years
44th
Morse Decoder
9th
Morse Encoder
8th
Niven Numbers
28th
Odious Numbers
37th
Ordinal Numbers
25th
Pascal’s Triangle
21st
Prime Numbers
28th
Roman to Arabic
24th
Seven Segment
18th
π
34th