Summation - Exponential series

Question

S = 1+3/1!+5/2!+7/3!......to infinity

 

a)e b)2e c)3e d)e-1

Answer 1

In addition to knowing the expansion of e as an infinite series here's another series that will help:

 

e = Σ [ k/k! ]

 

Can you figure out the answer?