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Number of n X n binary arrays symmetric under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.
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%I #5 Nov 25 2018 12:23:33

%S 1,1,1,1,4,7,16,35,133,363,1590,5600,33892,154647,1163836,6812622,

%T 66760064,504710757,6331779830,61565739001,996948455181,

%U 12487323542741,259917683188595,4189678086571772,112326942697897637

%N Number of n X n binary arrays symmetric under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

%K nonn

%O 1,5

%A _R. H. Hardin_, Oct 17 2008