Nested Sigma Noation

Just noting that one can always use limits to find the value when n approachs 1. Obviously you're not going to be able to find it exactly because it doesn't exist (infinity).

^Ehh... that GP you used is for |r|< 1 i.e. infinite GP series, so why are you plonking the interval=2 example into the |r| < 1 GP formula? Nobody does a sum to infinity for r > 1... But of course your point still stands.

Nevermind. Dumping 1 into the infinite GP formula still gives you infinity, which shows that it diverges (very loosely speaking).

Hadriel