Number of n X n 0..2 arrays with every nonzero element less than or equal to some NW, E or S neighbor.

A202981

Number of n X n 0..2 arrays with every nonzero element less than or equal to some NW, E or S neighbor.

Terms

    a(0) =1a(1) =9a(2) =1233a(3) =595202a(4) =2075667829

External references