Number of n X n symmetric binary matrices with each 1 adjacent to no more than 3 horizontally, vertically or diagonally neighboring 1s.

A191602

Number of n X n symmetric binary matrices with each 1 adjacent to no more than 3 horizontally, vertically or diagonally neighboring 1s.

Terms

    a(0) =2a(1) =8a(2) =52a(3) =686a(4) =16484a(5) =740480a(6) =62224406a(7) =9743390402

External references