Can the Summation Expression be Simplified?

[withoutwax]

I am wondering whether the following expression can be simplified

sum of( (p^n) / (n!) ) from n=1 to n=n.

 

[Dick]

It look pretty simple to me already. If you mean write it without the summation, I don't think so.

 

[HallsofIvy]

What do you mean by "n= n"? Did you mean
\sum_{n=1}^{N} \frac{p^n}{n!}?
I don't see any simple way to write that. However, it is well known that
\sum_{n=1}^\infty \frac{p^n}{n!}= e^p- 1