Number of 3Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

A221257

Number of 3Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Terms

    a(0) =0a(1) =16a(2) =30a(3) =2116a(4) =22268a(5) =488601a(6) =7356420a(7) =132273001a(8) =2175160988a(9) =37343243536a(10) =627439570380

External references