I'm sure he got there earlier than almost anyone! Just googled it, and it looks like he did is a little differently. He paired 1 with n and then 2 with n-1, et

I'm sure he got there earlier than almost anyone! Just googled it, and it looks like he did is a little differently. He paired 1 with n and then 2 with n-1, etc... yielding n/2 pairs that add up to n+1. It still works out to (n+1) * n/2, though :) Apparently biographers disagreed about his age at the time but they all had the same method and the same problem of summing numbers from 1 to 100.