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Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 110-111-110 pattern in any orientation.
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%I #4 Mar 31 2012 12:35:09

%S 1,1,1,1,1,1,2,5,10,17,30,77,254,873,2865,9282,36476,176379,950600,

%T 5334620,30998066,200015663,1516056134,12927161092,120013319909,

%U 1186872290095,12868902178120,156796551881590

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 110-111-110 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.1.1.1.0.0

%e .0.0.0.1.1.1.0.0

%e .0.0.0.0.1.0.1.1

%e .1.1.0.0.0.1.1.1

%e .1.1.1.0.0.0.1.1

%e .1.1.0.1.0.0.0.0

%e .0.0.1.1.1.0.0.0

%e .0.0.1.1.1.0.0.0

%K nonn

%O 1,7

%A _R. H. Hardin_