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

A300421

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

Terms

    a(0) =1a(1) =3a(2) =10a(3) =30a(4) =96a(5) =307a(6) =981a(7) =3137a(8) =10034a(9) =32096a(10) =102669a(11) =328423a(12) =1050581a(13) =3360673a(14) =10750367a(15) =34389071a(16) =110006322a(17) =351896433a(18) =1125672593a(19) =3600885592a(20) =11518781894a(21) =36847140260a(22) =117869385707a(23) =377049398986

External references