A146173 - OEIS

A146173

Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 110-100-111 pattern in any orientation.

%I #4 Mar 31 2012 12:35:09

%S 1,1,1,1,1,1,9,9,33,33,89,89,853,853,34557,34557,906369,906369,

%T 18920177,18920177,1254520087,1254520087,193995577775,193995577775

%N Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 110-100-111 pattern in any orientation.

%e Maximal 8 X 8 example

%e .1.0.0.0.0.0.0.1

%e .1.0.1.0.0.1.0.1

%e .1.1.1.0.0.1.1.1

%e .0.0.0.0.0.0.0.0

%e .1.1.1.0.0.1.1.1

%e .1.0.1.0.0.1.0.1

%e .1.0.0.0.0.0.0.1

%K nonn

%O 1,7

%A _R. H. Hardin_, Oct 27 2008