Abundant Numbers
50th
Arabic to Roman
24th
Christmas Trees
33rd
CSS Colors
27th
Cubes
19th
Diamonds
40th
Divisors
57th
Emirp Numbers
44th
Fizz Buzz
129th
Leap Years
55th
Look and Say
10th
Morse Decoder
17th
Niven Numbers
72nd
Prime Numbers
62nd
Quine
1st
Rule 110
17th
Seven Segment
24th
United States
23rd