A147227 - OEIS

A147227

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 11011-01110 pattern in any orientation.

%I #4 Mar 31 2012 12:35:16

%S 1,1,1,1,1,1,2,3,6,9,16,23,72,177,631,1684,5696,15819,69884,263612,

%T 1492069,6667995,40872228,203062570,1480955534,9070964673,81908729534

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 11011-01110 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.1.1.0.1.1.0

%e .0.0.0.1.1.1.0.1

%e .1.0.0.0.0.0.1.1

%e .1.1.0.0.0.0.1.0

%e .0.1.0.0.0.0.1.1

%e .1.1.0.0.0.0.0.1

%e .1.0.1.1.1.0.0.0

%e .0.1.1.0.1.1.0.0

%K nonn

%O 1,7

%A _R. H. Hardin_, Nov 04 2008