Number of nX4 0..1 arrays with every element equal to 0, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

A301604

Number of nX4 0..1 arrays with every element equal to 0, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

Terms

    a(0) =1a(1) =3a(2) =8a(3) =25a(4) =65a(5) =226a(6) =755a(7) =2539a(8) =8794a(9) =30539a(10) =106401a(11) =371492a(12) =1298761a(13) =4544515a(14) =15909548a(15) =55710973a(16) =195119181a(17) =683443550a(18) =2394043807a(19) =8386437959a(20) =29378680446a(21) =102918338575a(22) =360542635085

External references