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

A218813

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

Terms

    a(0) =1a(1) =225a(2) =3843a(3) =63499a(4) =1015637a(5) =16247233a(6) =259935681a(7) =4158793313a(8) =66538666069

External references