121609domain: NPropertiesPrimalityPrimeyesAppears in sequencesSmallest prime of the form 1 followed by a perfect power.at n=27A089773Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,0 3,1 4,0 5,1 6,1 polyhexes in any orientation on a planar n X n X n triangular grid.at n=8A155414Prime numbersat n=11447