12 Days of Christmas
46th
99 Bottles of Beer
36th
Abundant Numbers
Arabic to Roman
24th
Christmas Trees
66th
CSS Colors
34th
Cubes
Diamonds
11th
Divisors
31st
Emirp Numbers
Evil Numbers
83rd
Fibonacci
1st
Fizz Buzz
57th
Happy Numbers
Kolakoski Sequence
25th
Leap Years
44th
Look and Say
22nd
Niven Numbers
48th
Odious Numbers
61st
Ordinal Numbers
35th
Pangram Grep
42nd
Pernicious Numbers
42nd
Prime Numbers
37th
Quine
1st
RecamΓ‘n
32nd
Rule 110
18th
Seven Segment
36th
Spelling Numbers
21st
Tongue-twisters
20th
United States
31st
Vampire Numbers
34th
Van Eck Sequence
21st
Ο
44th248th80th23rd440th61st12th
Ο
24th120th
8th
Ο
24th
8th
β2
31st
9th
π
33rd
7th