12 Days of Christmas
6th
Abundant Numbers
20th
Abundant Numbers (Long)
17th
Arabic to Roman
2nd
Catalan’s Constant
21st
Collatz
Divisors
1st
Evil Numbers
6th
Evil Numbers (Long)
4th
Fibonacci
1st
Fizz Buzz
48th
Leap Years
27th
Look and Say
16th
Odious Numbers
6th
Odious Numbers (Long)
4th
Quine
1st
Tongue-twisters
22nd