12 Days of Christmas
8th
99 Bottles of Beer
6th
Abundant Numbers
24th
Christmas Trees
5th
CSS Colors
5th
Diamonds
6th
Divisors
10th
Emirp Numbers
Fibonacci
42nd
Fizz Buzz
26th483rd1,419th
Happy Numbers
30th
Intersection
3rd
Leap Years
12th
Morse Decoder
3rd
Morse Encoder
3rd
Niven Numbers
29th
Prime Numbers
30th
Seven Segment
5th
Sierpiński Triangle
10th
Tongue-twisters
16th
United States
7th