12 Days of Christmas
53rd
99 Bottles of Beer
37th
Abundant Numbers
65th
Arabic to Roman
27th
Christmas Trees
74th
CSS Colors
37th
Cubes
18th
Diamonds
22nd
Divisors
33rd
Emirp Numbers
44th
Evil Numbers
92nd
Fibonacci
1st
Fizz Buzz
65th
Happy Numbers
40th
Kolakoski Sequence
29th
Leap Years
48th
Look and Say
31st
Niven Numbers
53rd
Odious Numbers
70th
Ordinal Numbers
38th
Pangram Grep
45th
Pernicious Numbers
51st
Prime Numbers
40th
Quine
1st
Recamán
36th
Rule 110
22nd
Seven Segment
41st
Spelling Numbers
23rd
Tongue-twisters
26th
United States
34th
Vampire Numbers
37th
Van Eck Sequence
25th
π
48th280th87th26th494th63rd14th
τ
29th133rd
9th
φ
29th
9th
√2
36th
10th
𝑒
35th
8th