12 Days of Christmas
47th
99 Bottles of Beer
36th
Abundant Numbers
63rd
Arabic to Roman
27th
Christmas Trees
72nd
CSS Colors
34th
Cubes
16th
Diamonds
21st
Divisors
31st
Emirp Numbers
42nd
Evil Numbers
86th
Fibonacci
1st
Fizz Buzz
60th
Happy Numbers
35th
Kolakoski Sequence
25th
Leap Years
44th
Look and Say
28th
Niven Numbers
49th
Odious Numbers
65th
Ordinal Numbers
36th
Pangram Grep
43rd
Pernicious Numbers
46th
Prime Numbers
37th
Quine
1st
RecamΓ‘n
34th
Rule 110
21st
Seven Segment
38th
Spelling Numbers
22nd
Tongue-twisters
21st
United States
31st
Vampire Numbers
36th
Van Eck Sequence
22nd
Ο
44th259th81st24th452nd62nd13th
Ο
24th122nd
8th
Ο
24th
8th
β2
32nd
9th
π
34th
7th