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

A301886

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

Terms

    a(0) =4a(1) =13a(2) =29a(3) =58a(4) =125a(5) =331a(6) =823a(7) =2086a(8) =5269a(9) =13305a(10) =33569a(11) =85096a(12) =215567a(13) =546143a(14) =1383865a(15) =3506890a(16) =8886317a(17) =22519583a(18) =57069217a(19) =144624880a(20) =366509807a(21) =928817445a(22) =2353826833a(23) =5965120912a(24) =15116952851a(25) =38309747249a(26) =97085489873a(27) =246036440460

External references