Number of 3Xn 0..3+n-2 arrays with upper left zero and lower right 3+n-2 and each element differing from its horizontal and antidiagonal neighbors by one or two.

A265468

Number of 3Xn 0..3+n-2 arrays with upper left zero and lower right 3+n-2 and each element differing from its horizontal and antidiagonal neighbors by one or two.