Number of n X n symmetric binary matrices with each 1 adjacent to no more than 4 king-move neighboring 1's.

A191480

Number of n X n symmetric binary matrices with each 1 adjacent to no more than 4 king-move neighboring 1's.

Terms

    a(0) =2a(1) =8a(2) =51a(3) =624a(4) =14937a(5) =660986a(6) =54708660a(7) =8491650283

External references