Lagrange's three square theorem

Table 1 from Extended Lagrange's four-square theorem

PDF) Lagrange's Four-Square Theorem

Lagrange's four-square theorem

Table 3 from Extended Lagrange's four-square theorem

GitHub - HechenHu/Four-Square_Representation: Using Rabin and Shallit's Algorithm to compute the four-square representation of a natural number as stated in Lagrange's Four-square Theorem.

Lagrange's Four Squares Theorem

PDF) Quarternions and the Four Square Theorem

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

PPT - Waring's Problem PowerPoint Presentation, free download - ID:4504701

Sum of two squares theorem - Wikipedia