Abundant Numbers
60th
Arabic to Roman
31st
Christmas Trees
40th
CSS Colors
31st
Cubes
23rd
Diamonds
48th
Divisors
74th
Emirp Numbers
54th
Fizz Buzz
154th
Leap Years
70th
Look and Say
20th
Morse Decoder
17th
Niven Numbers
90th
Prime Numbers
74th
Quine
30th
Rule 110
21st
Seven Segment
29th
United States
28th