A146385 - OEIS

A146385

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0110-1111 pattern in any orientation.

%I #4 Mar 31 2012 12:35:10

%S 1,1,1,1,1,2,3,6,11,18,47,140,456,1541,4859,19189,88716,477610,

%T 2733493,16377324,107101430,821473645,7043526337,68487711150,

%U 704897480220,8110505465029,102402264000312,1483223734585349,23560655031075409

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0110-1111 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.0.0.0.0

%e .0.0.1.1.1.1.0.0

%e .0.1.0.1.1.0.1.0

%e .0.1.1.0.0.1.1.0

%e .0.1.0.1.1.0.1.0

%e .0.0.1.1.1.1.0.0

%e .0.0.0.0.0.0.0.0

%K nonn

%O 1,6

%A _R. H. Hardin_