Need books/articles with proofs of polygonal number theorem

Wretchosoft

I am giving a short presentation on Fermat's polygonal number theorem (any number may be written as the sum of n n-gonal numbers). I need books that provide some exposition/history on the theorem as well as a proof. I acquired Nathanson's Additive Number Theory from my university's library, but I'm not sure where to find more on the subject.

Oh, and the proofs should preferably be elementary, as I really know no number theory at all.

weichi

Wow, quite a coincidence - I just read chapter 3 of Stillwell, "Mathematics and Its History", which mentions this result! He says it was proved by Cauchy in 1813, with a "short" proof by Nathanson in 1987 (Proc Am Math Soc, 99, 22-24).

good luck!