# Recursion Formula

1. Nov 7, 2004

### Poweranimals

Do you guys know what the recursion formula for this series?

2. Nov 8, 2004

### Tide

If

$$a_n = r^n$$

then

$$a_{n+1} = r^{n+1} = r \times r^n = r a_n$$

but you knew that! :-)