Pythagorean triple

Three integers a, b, c such that a² + b² = c² are said to form a Pythagorean triple.

There are infinitely many Pythagorean triples.

Every Pythagorean triple has the form

a = m² - n²,

b = 2mn,

c = m² + n²

(possibly with a and b interchanged).

[Fermat's last theorem]? concerns a generalization of Pythagorean triples.