# Thread: Express in sigma notation

1. ## Express in sigma notation

nb

2. Originally Posted by oceanmd
$1/e+2/e^2+3/e^3+4/e^4+....+an$ (n lower than a)

I am not sure how to do it.
Is it sigma sign, on top n, on the botton k+1, next to it k/e^k

Please write the correct solution.

Thank you
is this what you are describing? $\sum_{k = 1}^{n} \frac k{e^k}$

3. Originally Posted by oceanmd
Yes, I am still learning how to code, but this is exactly what I meant.
So is it correct?
yes