I am reminded of Ramanujan's proof that the sum of all positive integers is -1 / 12. The Wikipedia article has a fascinating excerpt from his letter to Dr. Har

I am reminded of Ramanujan's proof that the sum of all positive integers is -1 / 12. The Wikipedia article has a fascinating excerpt from his letter to Dr. Hardy: http://en.wikipedia.org/wiki/1_%2B_2_%2B_3_%2B_4_%2B_%E2%80%A6 http://en.wikipedia.org/wiki/1_%2B_2_%2B_3_%2B_4_%2B_%E2%80%...