Given the Diophantine equation $$ x^2(8x-3)=y^2z, $$ is there a way to efficiently count the number of solutions that satisfy $x+y+z\leq n$, where $n$ is a fixed given integer? Also, for any fixed $x$, is it possible to count all such solutions $(x,y,z)$ without having to explicitly find all the divisors of $x^2(8x-3)$? A hint or a reference (if this is, in fact, easy) would be quite helpful. I asked this on [MSE][1], but got no responses. [1]: http://math.stackexchange.com/questions/456946/count-number-of-positive-integer-solutions-of-x28x-3-y2z