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Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected in a 3X2 elbow 1,1 1,2 1,3 2,3 in any orientation.
0

%I #3 Mar 31 2012 12:35:08

%S 1,1,1,9,31,205,1307,12227,171281,3266929,85166971,3120438693,

%T 149314103237,10059913232521,894685834014771

%N Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected in a 3X2 elbow 1,1 1,2 1,3 2,3 in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.1.1.0.1.1

%e .1.0.0.1.0.1.0.1

%e .1.0.0.1.0.1.0.1

%e .1.1.0.0.1.1.0.0

%e .0.0.1.1.0.0.1.1

%e .1.0.1.0.1.0.0.1

%e .1.0.1.0.1.0.0.1

%e .1.1.0.1.1.0.0.0

%K nonn

%O 1,4

%A _R. H. Hardin_, Oct 25 2008