# Harmonic factorial series sum

1. Mar 13, 2017

### terryds

1. The problem statement, all variables and given/known data

What is the value of $\frac{1}{1!} + \frac{1}{2!} + \frac{1}{3!} + \frac{1}{4!} + ...$ ?

2. Relevant equations

I have no idea since it's neither a geometric nor arithmatic series

3. The attempt at a solution

My Calculus purcell book tells me that it is e - 1 ≈ 1.718

But there are no ideas in it.

2. Mar 13, 2017

### haruspex

Do you know how to find the Taylor series of a function? If so, consider ex.