The series diverges.
When n >4, each term in
∞
∑ (n!/3n) > ∑1/n
n=0
∑1/n is a well known divergent series. Hence by the comparison test, the above series diverges.
∑ (n!/3n) > ∑1/n
n=0
∑1/n is a well known divergent series. Hence by the comparison test, the above series diverges.