255284domain: NAppears in sequencesNumber of ways to place zero or more nonadjacent 1,1 2,1 2,2 3,0 3,1 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155231Engel expansion of x value of the unique pairwise intersection on (0,1) of distinct order 5 power tower functions with parentheses inserted.at n=11A199880