Quote by steven187
so your sayin that it is possible in some cases to derive a formula for a series besides a geometric series but in most cases its not possible?

Yes. saltydog's given numerous examples. Telescoping series is another handy one, so is recognizing your sum as a known power series, rearranging terms sometimes helps, and more .
Quote by steven187
, and about that series it was suppose to be
[tex]\sum_{n=1}^{\infty}\frac {(2)^{n}}{n+1}[/tex]
like would i be able to derive a formula for this series? or how would i be able to find the sum of such a series?

Relate it to the power series for log(1+x).