Number of n X 1 0..4 arrays with no element equal to another at a city block distance of exactly two, and new values 0..4 introduced in row major order.

A222939

Number of n X 1 0..4 arrays with no element equal to another at a city block distance of exactly two, and new values 0..4 introduced in row major order.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =7a(4) =20a(5) =66a(6) =238a(7) =902a(8) =3510a(9) =13846a(10) =54998a(11) =219222a(12) =875350a(13) =3498326a(14) =13987158a(15) =55936342a(16) =223720790a(17) =894834006a(18) =3579237718a(19) =14316754262a(20) =57266623830a(21) =229065708886a(22) =916261262678

External references