Sum of two squares theorem - Wikipedia

Jacobi's four-square theorem - Wikipedia

What's so interesting about squared numbers? Lagrange's Four Square Theorem

GitHub - crteezy/java-lagrange-four-square-algorithm: Lagrange's four-square theorem algorithm using Java recursion

SOLUTION: Lagrange s four square theorem - Studypool

Square Number Definition & Meaning

Number Theory Sums of Squares Part 7.

number theory - The Four Square Theorem and Integral Apollonian Circle Packings, is there any connection? - Mathematics Stack Exchange

CodeChef - Lagrange's four-square theorem, also known as Bachet's conjecture, states that every natural number can be represented as the sum of four integer squares. This theorem was proven by Joseph Louis

Proving the Pythagorean Theorem. Some algebraic and geometric proofs of…, by Michele Diodati, Not Zero

Waring's Problem -- from Wolfram MathWorld