Abundant Numbers
56th
Arabic to Roman
29th
Christmas Trees
38th
CSS Colors
30th
Cubes
21st
Diamonds
45th
Divisors
68th
Emirp Numbers
52nd
Fizz Buzz
145th
Leap Years
63rd
Look and Say
15th
Morse Decoder
17th
Niven Numbers
85th
Prime Numbers
71st
Quine
20th
Rule 110
20th
Seven Segment
26th
United States
26th