12 Days of Christmas
32nd
99 Bottles of Beer
17th
Arabic to Roman
44th
Christmas Trees
13th
Cubes
9th
Diamonds
10th
Divisors
25th
Emirp Numbers
21st
Evil Numbers
25th
Fibonacci
23rd
Fizz Buzz
17th
Fractions
11th
Leap Years
15th
20th
Odious Numbers
25th
Pernicious Numbers
15th
Quine
1st715th
Sierpiński Triangle
11th
Spelling Numbers
44th
Tongue-twisters
11th
λ
9th