Number of nX4 0..1 arrays with every element equal to 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

A301995

Number of nX4 0..1 arrays with every element equal to 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =2a(1) =8a(2) =26a(3) =74a(4) =200a(5) =530a(6) =1394a(7) =3656a(8) =9578a(9) =25082a(10) =65672a(11) =171938a(12) =450146a(13) =1178504a(14) =3085370a(15) =8077610a(16) =21147464a(17) =55364786a(18) =144946898a(19) =379475912a(20) =993480842a(21) =2600966618a(22) =6809419016a(23) =17827290434a(24) =46672452290a(25) =122190066440a(26) =319897747034

External references