Is there a list of formulas for geometric series?

Question

For example:

$1 + 2 + 3 + ... + n = \frac{n(n+1)}{2}$

$1+x+x^2+...+x^{n-1}=\frac{x^n-1}{x-1}$

I'm sure there are many more but there doesn't seem to be any source that has a list of these formulas.

Answer 1

Well, for arithmetic sums:

$\displaystyle \sum_{x=1}^{n}x^2=\frac{n(n+1)(2n+1)}{6}$

$\displaystyle \sum_{x=1}^{n}x^3=\frac{n^2(n+1)^2}{4}$

Finally, an infinite series that is $a+ar+ar^2...=\displaystyle \frac{a}{1-r}$