Hi shawsend,

it seems that you obtain a difference equation (or a recursion), but just as in the theory of differential equations, you can not always solve a difference equation if its not a special type, i.e., linear constant coefficients or ect, either. Therefore, it is not very surprising that you may not have an explicit formula for it. I just wanted to note this.

But I hope I can find what you want...

bkarpuz