Number of nX2 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

A317759

Number of nX2 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =2a(1) =6a(2) =10a(3) =20a(4) =42a(5) =89a(6) =190a(7) =407a(8) =873a(9) =1874a(10) =4024a(11) =8642a(12) =18561a(13) =39866a(14) =85627a(15) =183917a(16) =395034a(17) =848492a(18) =1822474a(19) =3914489a(20) =8407926a(21) =18059375a(22) =38789713a(23) =83316386a(24) =178955184a(25) =384377666a(26) =825604417a(27) =1773314930a(28) =3808901427a(29) =8181135701

External references