12 Days of Christmas
26th
99 Bottles of Beer
34th
Abundant Numbers
21st
Arabic to Roman
27th
Christmas Trees
14th
Divisors
22nd
Emirp Numbers
25th
Evil Numbers
53rd
Fibonacci
1st
Fizz Buzz
47th
Foo Fizz Buzz Bar
19th
Happy Numbers
58th
Leap Years
24th
Niven Numbers
34th
Odious Numbers
52nd
Ordinal Numbers
22nd
Pangram Grep
10th
Pascal’s Triangle
35th
Pernicious Numbers
45th
Prime Numbers
42nd
Roman to Arabic
14th
Seven Segment
18th
Spelling Numbers
United States
24th
λ
15th
π
28th
τ
21st
φ
33rd
√2
39th
𝑒
29th