Simplify as one expression

1. Mar 12, 2005

irony of truth

I need some help

I got an expression involving series...

x - (2/6)x^3 - (20/120)x^5 - (1080/5040)x^7 - (140400/362880)x^9 - ...

I remove x from my summation expression.. but

Right now, I can express as a summation from n = 1 to infinity of

(??) x^(2n + 1) / (2n + 1)!

That is.. what is my pattern in this: 2, 20, 1080, 140400,... ?

2. Mar 13, 2005

relinquished™

Am I correct to say that you want to find the general term to express it as one summation?

3. Mar 13, 2005

irony of truth

Yes. That is what I want to know... thank you for your clarification