532199domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that remain prime through 5 iterations of function f(x) = 9x + 2.at n=27A023352Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,0 2,1 2,2 3,1 3,2 polyhexes in any orientation on a planar n X n X n triangular grid.at n=9A155356Prime numbersat n=43989