15095808domain: NAppears in sequencesa(n) = 2*a(n-2) + 4*a(n-3), with initial terms 0, 3, 3.at n=24A134068Numbers of directed Hamiltonian paths in the complete tripartite graph K_{n,n,n}.at n=3A234633Number of ways to shuffle a deck of 4n cards, with 4 cards in each of n ranks, so that adjacent cards have different ranks.at n=3A330266