What is this thing going to evaluate to? Well, this is going to evaluate to two times f of, when n is equal to one, this is one, f of one, plus two times, when n is two, this is going to be f of two times two minus one is three, f of three. When n is three, this is going to be two times f of five. When n is four, this is going to be two times, two times f of seven. Four times two minus one is seven. f of seven. And so that is going to be, we're going to have to evaluate a bunch of these things over here.