MD-MO 2007 Problem 6

Define $(b_{n})$ to be: $b_{0}=12$ , $b_{1}=\frac{\sqrt{3}}{2}$ adn $b_{n+1}+b_{n-1}=b_{n}\cdot\sqrt{3}$ . Find $b_{0}+b_{1}+\dots+b_{2007}$ .

Note. Maybe this seems too easy, but I want to post all the problems...