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. So let me actually, let me clear this out so I have a little bit more real estate. I'm feeling this might get a little bit messy now. So this is going to be, actually we could factor out a two.