Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor, with no occupancy greater than 2.

A221298

Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor, with no occupancy greater than 2.

Terms

    a(0) =7a(1) =137a(2) =2899a(3) =63285a(4) =1388449a(5) =30470039a(6) =668597561a(7) =14670167777a(8) =321884724335

External references