Number of 4Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns.

A221554

Number of 4Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns.

Terms

    a(0) =4a(1) =494a(2) =47976a(3) =4107189a(4) =354947070a(5) =30632388919

External references