Number of n X n 0..2 arrays avoiding the patterns z z+1 z or z z-1 z in any row, column or nw-se diagonal.

A207222

Number of n X n 0..2 arrays avoiding the patterns z z+1 z or z z-1 z in any row, column or nw-se diagonal.

Terms

    a(0) =3a(1) =81a(2) =6819a(3) =3447649a(4) =8779228417

External references