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

A144053

Number of n X n binary arrays, symmetric under horizontal reflection, 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) =4a(2) =5a(3) =25a(4) =357a(5) =4765a(6) =90553a(7) =3100249a(8) =146194232a(9) =11993787067

External references