608856domain: NAppears in sequencesNumber of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,1 5,1 6,2 7,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=9A155419Triangular numbers (A000217) that are also centered pentagonal numbers (A005891).at n=5A254628