A146380 - OEIS

A146380

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0100-1111-0100 pattern in any orientation.

%I #4 Mar 31 2012 12:35:10

%S 1,1,1,1,1,13,27,135,527,2581,17899,176183,1596080,23232289,321756402,

%T 6986541337,150961652645,4812704574943,154830665386988

%N Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0100-1111-0100 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.0.1.0.0

%e .0.0.0.0.1.1.1.1

%e .0.1.0.0.0.1.0.0

%e .1.1.1.1.0.0.1.0

%e .0.1.0.0.1.1.1.1

%e .0.0.1.0.0.0.1.0

%e .1.1.1.1.0.0.0.0

%e .0.0.1.0.0.0.0.0

%K nonn

%O 1,6

%A _R. H. Hardin_