Suppose there is an equation $a^2 - b^2 = X$
how many pairs of $(a,b)$ exist to find $X$, when $a,b$ and $X$ are positive integers.
It would be great if you could direct to proof although not necessary.
An example: $a = 13, b = 11 X = 48$.
13^2 - 11^2 = 48
how many more $(a,b)$ pairs exist for 48? How to find out/them ?
I am not a Maths student although i see that this is a variant of a 'diophantine equation'?