I am trying to find a formula that will take a sum of a series of powers
without having to use a load of IF statements. Here is what I need:

User inputs a positive number, y and excel a constant number, x, to calulate
the following:

X+X^2+X^3+X^4+....+X^Y.

It appears that series sum is not capable of doing this, as it adds another
factor to the equation, multiplying a times X, with a changing for each term.


Anyone have any ideas?

Thanks.