12 Days of Christmas
15th
Christmas Trees
15th
Diamonds
19th
Divisors
31st
Emirp Numbers
15th
Evil Numbers
15th
Fibonacci
63rd
Fizz Buzz
65th
Happy Numbers
15th
Niven Numbers
37th
Odious Numbers
18th
Pangram Grep
49th
Pascal’s Triangle
30th
Pernicious Numbers
30th
Prime Numbers
32nd
Quine
1st
π
15th
τ
14th