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Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 101-111-010 pattern in any orientation.
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%I #4 Mar 31 2012 12:35:09

%S 1,1,1,1,3,9,20,63,272,1557,10412,77761,729051,8641753,126757272,

%T 2289847876,50015283552,1327280079169,43398915228962,1753679030593542,

%U 87293853894564783,5311141506545315135,394710940436034575590

%N Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 101-111-010 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.1.1.0.0.0

%e .0.0.1.1.0.0.0.0

%e .0.1.0.1.1.0.0.0

%e .1.1.1.0.0.1.0.1

%e .1.0.1.0.0.1.1.1

%e .0.0.0.1.1.0.1.0

%e .0.0.0.0.1.1.0.0

%e .0.0.0.1.1.0.0.0

%K nonn

%O 1,5

%A _R. H. Hardin_