Abundant Numbers
43rd
Christmas Trees
33rd
Day of Week
1st
Diamonds
15th
Divisors
1st
Emirp Numbers
11th
Fibonacci
1st
Fizz Buzz
12th
Leap Years
33rd
ln 2
10th
Look and Say
20th
Ordinal Numbers
11th
Pangram Grep
20th
Pascal’s Triangle
19th
Pernicious Numbers
34th
Prime Numbers
26th
Quine
1st
Recamán
10th