Number of nX3 0..1 arrays with every element unequal to 0, 1, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

A318540

Number of nX3 0..1 arrays with every element unequal to 0, 1, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =3a(1) =3a(2) =6a(3) =13a(4) =26a(5) =52a(6) =107a(7) =218a(8) =442a(9) =899a(10) =1829a(11) =3720a(12) =7565a(13) =15384a(14) =31288a(15) =63632a(16) =129408a(17) =263180a(18) =535236a(19) =1088521a(20) =2213749a(21) =4502149a(22) =9156120a(23) =18621004a(24) =37869943a(25) =77016935a(26) =156631035a(27) =318543977a(28) =647829886a(29) =1317505875

External references