square number

Brahmagupta–Fibonacci identity – Expression of a product of sums of squares as a sum of squares

Cubic number – Number raised to the third power

Euler's four-square identity – Product of sums of four squares expressed as a sum of four squares

Fermat's theorem on sums of two squares – Condition under which an odd prime is a sum of two squares

Some identities involving several squares

Integer square root – Greatest integer less than or equal to square root

Methods of computing square roots – Algorithms for calculating square roots

Power of two – Two raised to an integer power

Pythagorean triple – Integer side lengths of a right triangle

Quadratic residue – Integer that is a perfect square modulo some integer

Quadratic function – Polynomial function of degree two

Square triangular number – Integer that is both a perfect square and a triangular number