  In the packing-constrained point covering problem, PC^2, one seeks
configurations of points in the plane that cannot all be covered by a packing
arrangement of unit disks. We consider in particular the problem of finding the
minimum number of points N for which such a configuration exists and obtain the
bounds 11 <= N <= 55. The disparity of these bounds is symptomatic, we believe,
of the fact that PC^2 belongs in a higher complexity class than the standard
packing and covering problems.
