Jacobi's four-square theorem

Lagrange's four-square theorem - Wikipedia

Chit-chat on Lagrange's four-square theorem

PDF) A Simple Proof of Jacobi's Four-Square Theorem

5. * In the following sequence of problems, we will

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

FERMAT'S FOUR SQUARES THEOREM Several years ago, after

PDF] New parametrization of $A^2+B^2+C^2=3D^2$ and Lagrange's four-square theorem

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

Lagrange's Four-Square Theorem by Julian TSE

Euler's four-square identity - Wikipedia