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

A218188

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

Terms

    a(0) =1a(1) =15a(2) =507a(3) =65251a(4) =33407143a(5) =68410191725

External references