12 Days of Christmas
73rd
99 Bottles of Beer
80th
Abundant Numbers
61st
Christmas Trees
37th
Cubes
16th
Diamonds
32nd
Divisors
70th
Emirp Numbers
28th
Evil Numbers
60th
Fibonacci
54th
Fizz Buzz
116th
Happy Numbers
31st
Leap Years
89th
Morse Decoder
13th
Morse Encoder
14th
Niven Numbers
71st
Odious Numbers
61st
Ordinal Numbers
32nd
Pangram Grep
44th
Pascal’s Triangle
29th
Pernicious Numbers
50th
Prime Numbers
76th
Rule 110
27th
Seven Segment
14th
Sierpiński Triangle
37th
United States
λ
14th
π
33rd
τ
17th
φ
18th
√2
19th
𝑒
20th