12 Days of Christmas
80th
99 Bottles of Beer
83rd
Abundant Numbers
63rd
Christmas Trees
37th
Cubes
17th
Diamonds
33rd
Divisors
72nd
Emirp Numbers
28th
Evil Numbers
61st
Fibonacci
56th
Fizz Buzz
116th
Happy Numbers
33rd
Leap Years
90th
Morse Decoder
13th
Morse Encoder
15th
Niven Numbers
74th
Odious Numbers
63rd
Ordinal Numbers
33rd
Pangram Grep
45th
Pascal’s Triangle
30th
Pernicious Numbers
54th
Prime Numbers
79th
Rule 110
27th
Seven Segment
15th
Sierpiński Triangle
38th
United States
λ
15th
π
34th
τ
18th
φ
20th
√2
20th
𝑒
21st