Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

A318338

Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =4a(1) =10a(2) =20a(3) =36a(4) =76a(5) =160a(6) =344a(7) =748a(8) =1624a(9) =3544a(10) =7724a(11) =16856a(12) =36776a(13) =80252a(14) =175128a(15) =382168a(16) =833996a(17) =1819992a(18) =3971720a(19) =8667356a(20) =18914520a(21) =41276600a(22) =90076716a(23) =196571800a(24) =428972904a(25) =936135100a(26) =2042900376a(27) =4458162072a(28) =9728917388

External references