So is it that we don't know have a bound for generic N, or that we know a bound but haven't found it for N=14-18, >20?
I'm sure we know the bound exists, but I'm more interested in whether we've found a closed form (or even just analytic) way to express the bound.
There is at least one bound: When the unused surface is smaller than 1 disc is an absolute bound. Also, when all discs are touching 3-by-3, we can’t extract more space.
Which they then served as a blurry (in my browser, at least) gif. I have no idea which #'s are bold.
It's not referring to the images linked at the top, but the table at the bottom of the page. It's not an image.