is at most n*n-1 of course, and it actually attains this bound when n=5,7,29,79,103,149,173,197,199,269,271,293,... These n all are primes p with JacobSymbol[3,p]=-1 and JacobSymbol[-2,p]=-1. But they do not include every such prime since p=31 is not there. -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)