Project Euler

Problem #135

Given the positive integers, x, y, and z, are consecutive terms of an arithmetic progression, the least value of the positive integer, n, for which the equation, x^(2) − y^(2) − z^(2) = n, has exactly two solutions is n = 27:

34^(2) − 27^(2) − 20^(2) = 12^(2) − 9^(2) − 6^(2) = 27

It turns out that n = 1155 is the least value which has exactly ten solutions.

How many values of n less than one million have exactly ten distinct solutions?