Question 154
Determine, with proof, the smallest positive integer $N$ for which the equation
$$
x^2 - y^2 = N
$$
has exactly 24 solutions $(x, y)$ with positive integers $x$ and $y$.
$$
x^2 - y^2 = N
$$
has exactly 24 solutions $(x, y)$ with positive integers $x$ and $y$.