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Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-1100 pattern in any orientation.
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%I #4 Mar 31 2012 12:35:17

%S 1,1,1,1,1,1,1,1,4,7,14,21,38,89,317,871

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

%e Maximal 9 X 9 example

%e .0.0.0.0.1.1.0.0.0

%e .0.0.1.1.1.1.0.0.0

%e .0.1.0.0.1.1.0.0.0

%e .0.1.0.0.0.0.1.1.1

%e .1.1.1.0.0.0.1.1.1

%e .1.1.1.0.0.0.0.1.0

%e .0.0.0.1.1.0.0.1.0

%e .0.0.0.1.1.1.1.0.0

%e .0.0.0.1.1.0.0.0.0

%K nonn

%O 1,9

%A _R. H. Hardin_