Oh I see.. Well, I do also assume that your calculations are correct, but I would like to take a shot for the D = 3 case.

The equation is this, but I do not seem to get what k represents.

EDIT:

How do we call in English the d - i and k -i that lie into a parenthesis? You can see it in the link. I know how to calculate it.

The combination one can answer. Yes, that's true.

Assume we have the combination of n and k. In Greek, we can say n per k, can we say that in English too?