12 Days of Christmas
9th
99 Bottles of Beer
14th
Arabic to Roman
7th
Christmas Trees
13th
Divisors
34th
Emirp Numbers
12th
Evil Numbers
21st
Fibonacci
56th
Fizz Buzz
82nd
Happy Numbers
10th
Niven Numbers
46th
Odious Numbers
21st
Pascal’s Triangle
16th
Pernicious Numbers
23rd
Prime Numbers
38th
Quine
1st
Roman to Arabic
11th
Seven Segment
11th
Sierpiński Triangle
10th
π
11th