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Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111 pattern in any orientation.
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%I #4 Mar 31 2012 12:35:09

%S 1,1,1,1,1,1,3,7,15,27,53,167,715,3083,12351,50227,261707,1665665,

%T 12424027,97246107,810664323,7548517875,83664650731,1054301327283

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.1.1.0.0

%e .0.0.1.1.1.1.0.0

%e .0.1.0.0.0.0.1.1

%e .0.1.0.0.0.0.1.1

%e .1.1.0.0.0.0.1.0

%e .1.1.0.0.0.0.1.0

%e .0.0.1.1.1.1.0.0

%e .0.0.1.1.0.0.0.0

%K nonn

%O 1,7

%A _R. H. Hardin_