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Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 3X2 zee 1,1 1,2 1,3 2,3 2,4 in any orientation.
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%I #3 Mar 31 2012 12:35:09

%S 1,1,1,1,1,1,5,9,21,39,159,427,2501,9027,58503,271185,2371669,

%T 14600987,167228191,1344019107,19775648697,206847230557,3987249030381,

%U 54541478154327,1370106516904685,24431476697291095

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 3X2 zee 1,1 1,2 1,3 2,3 2,4 in any orientation.

%e Maximal 8 X 8 example

%e .0.0.1.1.1.0.0.0

%e .0.0.0.0.1.1.0.0

%e .1.0.0.0.0.0.1.0

%e .1.0.0.0.0.0.1.1

%e .1.1.0.0.0.0.0.1

%e .0.1.0.0.0.0.0.1

%e .0.0.1.1.0.0.0.0

%e .0.0.0.1.1.1.0.0

%K nonn

%O 1,7

%A _R. H. Hardin_, Oct 27 2008