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

A302266

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

Terms

    a(0) =2a(1) =8a(2) =29a(3) =105a(4) =384a(5) =1405a(6) =5135a(7) =18766a(8) =68589a(9) =250693a(10) =916272a(11) =3348929a(12) =12240187a(13) =44737350a(14) =163513041a(15) =597632937a(16) =2184322000a(17) =7983600501a(18) =29179707415a(19) =106650542494a(20) =389803024901

External references