99 Bottles of Beer
20th
Abundant Numbers
30th
Christmas Trees
31st
Divisors
34th
Emirp Numbers
22nd
Evil Numbers
46th
Fibonacci
85th
Fizz Buzz
160th
Leap Years
53rd
Morse Decoder
12th
Morse Encoder
11th
Niven Numbers
30th
Odious Numbers
42nd
Ordinal Numbers
29th
Pascal’s Triangle
24th
Prime Numbers
29th
Roman to Arabic
31st
Seven Segment
19th
π
43rd