I do enjoy these challenges. I played around with this table a bit and came up with something workable, I think.
I put the whole thing inside box lines. I had to break the rule about where to put that first equals sign in order to use the whole width of the page for the table portion which, miraculously, takes 40 cells.
I considered saving space by showing letters B G and N in lowercase, but since a lowercase n appears in the part below the table, this is not feasible.
What I ended up doing was keying -(BG/N^2)(1/N-1). If that is not giving away an answer somehow, I think it works. I blocked the runover of the fraction BG/N^2 because otherwise the table would not fit in 40 cells. By inserting a blank line between the rows, like we do in a matrix with runovers, I think this looks pretty good.
If you don't like this plan, using facing pages would be a good idea.
About row 3 in the table, the new Nemeth Code is hoping to offer new symbols for the vertical and diagonal ellipses. We can all look forward to that. In the meantime, for this project, transcribe the regular (3, 3, 3) horizontal ellipsis.