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

A191553

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

Terms

    a(0) =2a(1) =8a(2) =60a(3) =855a(4) =24282a(5) =1352976a(6) =146740728a(7) =31117674297

External references