Number of nX3 0..1 arrays with every element equal to 1, 2 or 4 horizontally or vertically adjacent elements, with upper left element zero.

A301664

Number of nX3 0..1 arrays with every element equal to 1, 2 or 4 horizontally or vertically adjacent elements, with upper left element zero.

Terms

    a(0) =1a(1) =10a(2) =30a(3) =118a(4) =407a(5) =1498a(6) =5289a(7) =19184a(8) =68832a(9) =247756a(10) =890523a(11) =3203084a(12) =11517675a(13) =41422044a(14) =148957388a(15) =535680672a(16) =1926390947a(17) =6927645818a(18) =24912983963a(19) =89591402294a(20) =322185988646

External references