68818domain: NAppears in sequencesNumber of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155246Constant term of the reduction by x^2->x+1 of the polynomial p(n,x) defined at Comments.at n=16A193008