Generate all Primitive Pythagorean Triplets with c less than a given number.

A Pythagorean Triplet is three numbers (a,b,c) such that

A Primitive Pythagorean Triplet means that there exists no such that is a common divisor for a,b and c. Or stated in other words a,b,c are coprimes.

Based on the primitive Pythagorean triplets you can generate all other triplets by multiplying a,b and c by an integer k.