Clear[a, n, r] a[n_] = Sin[Pi*n/2]/n! Table[a[n], {n, 0, 10}] r = Limit[Abs[a[n]]^(1/n), n -> Infinity]
What do I need to change to make MMA10.3 (OSX) give me an answer? Thanks for suggestions.
Gary Bollenbach
The following works in Mma 10.4:
Limit[Simplify[(Abs[Sin[Pi*n/2]]/n!)^(1/n) // TrigToExp, Element[n, Integers]], n -> Infinity, Assumptions -> Element[n, Integers]]
Thanks, that's what I needed.