99 Bottles of Beer
21st
Abundant Numbers
30th
Christmas Trees
31st
Divisors
36th
Emirp Numbers
23rd
Evil Numbers
47th
Fibonacci
88th
Fizz Buzz
162nd
Leap Years
54th
Morse Decoder
12th
Morse Encoder
11th
Niven Numbers
30th
Odious Numbers
44th
Ordinal Numbers
30th
Pascal’s Triangle
24th
Prime Numbers
29th
Roman to Arabic
31st
Seven Segment
20th
π
43rd