12 Days of Christmas
158
66174
67
99 Bottles of Beer
17
8
Abundant Numbers
175
Christmas Trees
73
Divisors
538
Emirp Numbers
270
Evil Numbers
280
Fibonacci
115
Fizz Buzz
327289159276
223218
Happy Numbers
286
Leap Years
315
31
Odious Numbers
269
Pascal’s Triangle
28
Pernicious Numbers
200
Prime Numbers
250
Quine
912
Rock-paper-scissors-Spock-lizard
192
Sierpiński Triangle
91
Smith Numbers
37
34
United States
69
Vampire Numbers
76
λ
89
π
259
39
τ
27
40
φ
103
25
√2
29
𝑒
29