The total number of perfect squares and perfect cubes for the same number would be: (15!)^(1/6) =104 such numbers. And these numbers will consist of ALL prime numbers up to: 10^[(log(15!))/ log(6)]=~105. The last prime number to be included would be 103.
However, all these prime numbers must be raised to a MINIMUM power of 6 and multiples of 6. So, the first of these numbers would look like this:
2^6, 2^12, 2^18, 2^24, 2^30, 2^36(which is < 15!). Then, they will continue with the next prime: 3^6, 3^12, 3^18....etc. Then you will have a combination of powers such as: 2^6 x 3^6 x 5^6 and multiples thereof.
The computer-generated numbers will begin with:
(1, 64, 729, 4096, 15625, 46656, 117649, 262144, 531441, 1000000........etc......and end in: 1000000000000, 1061520150601, 1126162419264, 1194052296529, 1265319018496), for a grand total = 104.