Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

A303508

Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =4a(1) =20a(2) =78a(3) =420a(4) =2088a(5) =9916a(6) =49740a(7) =245904a(8) =1204720a(9) =5966528a(10) =29461128a(11) =145208512a(12) =717277504a(13) =3540859200a(14) =17473224048a(15) =86264173904a(16) =425824598480

External references