A146721 - OEIS

A146721

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111-1000 pattern in any orientation.

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

%S 1,1,1,1,5,21,49,265,1337,7025,55305,543439,6271235,94294061,

%T 1709408045,38060613237

%N Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111-1000 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.1.1.1.0.1.1.1

%e .0.1.1.0.0.0.1.1

%e .0.0.1.0.0.0.1.0

%e .0.1.0.0.0.1.0.0

%e .1.1.0.0.0.1.1.0

%e .1.1.1.0.1.1.1.0

%K nonn

%O 1,5

%A _R. H. Hardin_, Nov 04 2008