1159587domain: NAppears in sequencesMagnetic Tower of Hanoi, number of moves of disk number k, optimally solving the [RED ; NEUTRAL ; BLUE] pre-colored puzzle.at n=14A183113a(n) = 2*binomial(9*n+2,n)/(9*n+2).at n=6A234505Number of nonequivalent noncrossing 4-gonal cacti with n polygons up to rotation.at n=8A361238