Number of n X n symmetric binary matrices with each 1 adjacent to no more than 2 diagonally or antidiagonally neighboring 1s.

A191552

Number of n X n symmetric binary matrices with each 1 adjacent to no more than 2 diagonally or antidiagonally neighboring 1s.

Terms

    a(0) =2a(1) =8a(2) =52a(3) =528a(4) =11275a(5) =435987a(6) =30448860a(7) =3920809305a(8) =920775496348

External references