Fermat's theorem on sums of two squares
= Fermat's theorem on sums of two squares
{wiki=Fermat's_theorem_on_sums_of_two_squares}
Fermat's theorem on sums of two squares states that an odd prime number \\( p \\) can be expressed as the sum of two squares (i.e., there exist integers \\( x \\) and \\( y \\) such that \\( p = x^2 + y^2 \\)) if and only if \\( p \\equiv 1 \\mod 4 \\) or \\( p = 2 \\).