How to sum this series?
$\displaystyle \sum_{n=0}^{\infty} \left( \left(\frac{1}{2}+\frac{1}{\sqrt{5}}\right)^n + \left(\frac{1}{2}-\frac{1}{\sqrt{5}}\right)^n \right)$
How to sum this series?
$\displaystyle \sum_{n=0}^{\infty} \left( \left(\frac{1}{2}+\frac{1}{\sqrt{5}}\right)^n + \left(\frac{1}{2}-\frac{1}{\sqrt{5}}\right)^n \right)$