Abundant Numbers
12th
Abundant Numbers (Long)
12th
Arithmetic Numbers
62nd
Ascending Primes
25th
Collatz
1,390th
Divisors
18th
Emirp Numbers
27th
Emirp Numbers (Long)
1st
Evil Numbers
1st
Evil Numbers (Long)
1st
Factorial Factorisation
33rd
Fibonacci
1st
Happy Numbers
1st
Happy Numbers (Long)
1st
ISBN
9th
Leap Years
1,850th
Look and Say
3rd
Lucky Numbers
325th
Niven Numbers
1st
Niven Numbers (Long)
1st
Odious Numbers
1st
Odious Numbers (Long)
1st
Ordinal Numbers
368th
Pascal’s Triangle
1st
Pernicious Numbers
21st
Pernicious Numbers (Long)
78th
Prime Numbers
1st
Prime Numbers (Long)
1st
Quine
1st