Abundant Numbers
38th
Christmas Trees
27th
Day of Week
1st
Diamonds
14th
Divisors
1st
Emirp Numbers
10th
Fibonacci
1st
Fizz Buzz
11th
Leap Years
28th
ln 2
9th
Look and Say
15th
Ordinal Numbers
8th
Pangram Grep
21st
Pascal’s Triangle
21st
Pernicious Numbers
31st
Prime Numbers
23rd
Quine
1st
Recamán
9th