Number of 4Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, without 2-loops or left turns.

A221789

Number of 4Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, without 2-loops or left turns.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =16a(4) =173a(5) =1325a(6) =15936a(7) =187794a(8) =2167196a(9) =25071259a(10) =290320330a(11) =3362811279a(12) =38954814644a(13) =451260930462

External references