A147040 - OEIS

A147040

Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 0100-0100-1111-0100 pattern in any orientation.

%I #4 Mar 31 2012 12:35:14

%S 1,1,1,1,1,1,1,1,3,3,5,5,9,9,21,21,69,69,305,305,1333,1333,6087,6087,

%T 37147,37147,280959,280959

%N Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 0100-0100-1111-0100 pattern in any orientation.

%e Maximal 9 X 9 example

%e .0.0.1.0.0.0.1.0.0

%e .1.1.1.1.0.1.1.1.1

%e .0.0.1.0.0.0.1.0.0

%e .0.0.0.0.0.0.0.0.0

%e .0.0.1.0.0.0.1.0.0

%e .1.1.1.1.0.1.1.1.1

%e .0.0.1.0.0.0.1.0.0

%K nonn

%O 1,9

%A _R. H. Hardin_, Nov 04 2008