Number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, with no occupancy greater than 2.

A221135

Number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, with no occupancy greater than 2.

Terms

    a(0) =4a(1) =289a(2) =12544a(3) =643204a(4) =31203396a(5) =1539699121a(6) =75512292025

External references