12 Days of Christmas
73rd
99 Bottles of Beer
78th
Abundant Numbers
61st
Christmas Trees
37th
Cubes
17th
Diamonds
32nd
Divisors
69th
Emirp Numbers
26th
Evil Numbers
57th
Fibonacci
46th
Fizz Buzz
109th
Happy Numbers
28th
Leap Years
82nd
Morse Decoder
12th
Morse Encoder
14th
Niven Numbers
69th
Odious Numbers
56th
Ordinal Numbers
31st
Pangram Grep
41st
Pascal’s Triangle
29th
Pernicious Numbers
49th
Prime Numbers
69th
Rule 110
26th
Seven Segment
13th
Sierpiński Triangle
35th
United States
λ
15th
π
31st
τ
18th
φ
19th
√2
20th
𝑒
20th