Hilltop maps: number of n X 4 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..3 n X 4 array.

A218806

Hilltop maps: number of n X 4 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..3 n X 4 array.

Terms

    a(0) =15a(1) =249a(2) =3969a(3) =63499a(4) =1015887a(5) =16252713a(6) =260019585a(7) =4159932363a(8) =66552822351

External references