A147127 - OEIS

A147127

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1000-1111-1000 pattern in any orientation.

%I #4 Mar 31 2012 12:35:15

%S 1,1,1,1,1,1,1,1,3,7,15,27,51,137,397,1327,4515,15837,61007,262125,

%T 1291801

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1000-1111-1000 pattern in any orientation.

%e Maximal 9 X 9 example

%e .0.0.0.1.1.1.1.0.0

%e .0.0.0.0.1.0.0.0.0

%e .0.0.0.0.1.0.0.0.1

%e .1.0.0.0.1.0.0.0.1

%e .1.1.1.1.0.1.1.1.1

%e .1.0.0.0.1.0.0.0.1

%e .1.0.0.0.1.0.0.0.0

%e .0.0.0.0.1.0.0.0.0

%e .0.0.1.1.1.1.0.0.0

%K nonn

%O 1,9

%A _R. H. Hardin_, Nov 04 2008