A146677 - OEIS

A146677

Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-0111-1100 pattern in any orientation.

%I #4 Mar 31 2012 12:35:11

%S 1,1,1,1,1,3,9,19,52,193,866,4709,29160,204475,1745781,17973283,

%T 218163477,3154013451,54291505832,1101846202608,26444293196609,

%U 754399567634635,25615826491870630,1034470468747498026

%N Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-0111-1100 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.1.1.0.0

%e .0.0.1.1.1.0.0.0

%e .0.1.0.0.1.1.0.0

%e .0.1.0.0.0.0.0.0

%e .1.1.1.0.0.0.0.0

%e .1.0.1.0.0.0.0.0

%e .0.0.0.0.0.0.0.0

%K nonn

%O 1,6

%A _R. H. Hardin_, Nov 04 2008