I did this page a while ago, but don't think I told you guys about it: Taylor Series
Comments and suggestions welcome!
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
I say leave it as it is. It is a good introduction.
In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.