Number of n X n binary arrays, symmetric under 180 degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically.

A144059

Number of n X n binary arrays, symmetric under 180 degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically.

Terms

    a(0) =1a(1) =2a(2) =7a(3) =43a(4) =317a(5) =4395a(6) =85883a(7) =3189035a(8) =155707292a(9) =14992855085

External references