Number of n X n symmetric binary matrices containing no more than two 1s in any 3 X 3 sub-block.

A139010

Number of n X n symmetric binary matrices containing no more than two 1s in any 3 X 3 sub-block.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =10a(4) =46a(5) =298a(6) =1984a(7) =21540a(8) =331078a(9) =6336017a(10) =173488605a(11) =6651795802a(12) =340061007958

External references