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

A221133

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

Terms

    a(0) =0a(1) =9a(2) =656a(3) =643204a(4) =4235650596

External references