440756domain: NAppears in sequencesNumber of planted identity trees where non-root, non-leaf nodes an even distance from root are of degree 2.at n=26A007560Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,1 4,1 5,1 polyhexes in any orientation on a planar nXnXn triangular grid.at n=8A155296