99 Bottles of Beer
19th
Abundant Numbers
29th
Christmas Trees
30th
Divisors
33rd
Emirp Numbers
22nd
Evil Numbers
46th
Fibonacci
80th
Fizz Buzz
158th
Leap Years
48th
Morse Decoder
11th
Morse Encoder
10th
Niven Numbers
30th
Odious Numbers
42nd
Ordinal Numbers
26th
Pascal’s Triangle
22nd
Prime Numbers
28th
Roman to Arabic
28th
Seven Segment
19th
π
40th