12 Days of Christmas
45th
99 Bottles of Beer
35th
Abundant Numbers
60th
Arabic to Roman
27th
Christmas Trees
70th
CSS Colors
32nd
Cubes
15th
Diamonds
20th
Divisors
31st
Emirp Numbers
41st
Evil Numbers
83rd
Fibonacci
1st
Fizz Buzz
54th
Happy Numbers
35th
Kolakoski Sequence
25th
Leap Years
44th
Look and Say
28th
Niven Numbers
48th
Odious Numbers
65th
Ordinal Numbers
35th
Pangram Grep
42nd
Pernicious Numbers
45th
Prime Numbers
38th
Quine
1st
RecamΓ‘n
33rd
Rule 110
21st
Seven Segment
38th
Spelling Numbers
22nd
Tongue-twisters
19th
United States
30th
Vampire Numbers
35th
Van Eck Sequence
22nd
Ο
42nd243rd79th23rd425th60th12th
Ο
23rd118th
Ο
24th
β2
31st
π
33rd