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

A302225

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

Terms

    a(0) =0a(1) =3a(2) =14a(3) =45a(4) =146a(5) =537a(6) =1934a(7) =6861a(8) =24386a(9) =86913a(10) =309638a(11) =1102677a(12) =3927050a(13) =13986633a(14) =49814510a(15) =177416541a(16) =631877618a(17) =2250466449a(18) =8015156630a(19) =28546401765a(20) =101669514458a(21) =362101348953

External references