Talk:Squared triangular number
Latest comment: 15 years ago by CRGreathouse in topic Proof
It would be nice to include the picture proof from http://users.tru.eastlink.ca/~brsears/math/oldprob.htm#s32, since it is clearer than the one already on this page, but I am not sure about the copyright status of the images. Please advise.
Loeb 02:17, 30 October 2007 (UTC)
- It is a pretty proof. I think only the second of the two images there can easily stand on its own. BUT, I would like to know the source of the proof. Has it been published anywhere? Is it the same as one of the existing proofs already known in the article? I don't think a web page makes an adequate reference for a problem with as much history as this one. —David Eppstein 02:22, 30 October 2007 (UTC)
Proof
Who was the first to prove this theorem? I've seen it called Nicomachus' Theorem, but did he prove it or merely observe it? If not, did Āryabhaṭa? Al-Karajī?