EntityQ756946· pop 27· linked from 60 articlesLagrange's four-square theoremSign in to savetheoremConnectionsSrinivasa RamanujanEntityJoseph-Louis LagrangeEntityDiophantus of AlexandriaEntityFermat polygonal number theoremEntityYouTubeConceptInternational Standard Book NumberEntitynatural numberEntityprime numberEntityintegerEntityrational numberEntitydigital object identifierEntitysquare rootEntityG.H. HardyEntityLagrangian pointEntityquaternionEntityringEntityCarl Gustav Jacob JacobiEntityAndrew WilesEntitydivisorEntityQ118398EntityCategoriesAdditive number theorySquares in number theoryTheorems in number theory