Number of n X n 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 2 neighboring 1's.

A296321

Number of n X n 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 2 neighboring 1's.

Terms

    a(0) =1a(1) =3a(2) =11a(3) =61a(4) =853a(5) =20088a(6) =850404a(7) =72224019a(8) =11207386103

External references