Number of nX4 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns.

A221550

Number of nX4 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) =503a(2) =48018a(3) =4107189a(4) =354544219a(5) =30591390580

External references