A146070 - OEIS

A146070

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 5-point zee 1,1 2,1 2,2 2,3 3,3 in any orientation.

%I #3 Mar 31 2012 12:35:09

%S 1,1,5,1,9,25,101,401,3215,13761,224503,1483715,30996399,381934429,

%T 12283193557,226607791453,11864500856825

%N Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 5-point zee 1,1 2,1 2,2 2,3 3,3 in any orientation.

%e Maximal 8 X 8 example

%e .0.1.1.0.0.0.1.0

%e .0.1.0.0.1.1.1.0

%e .1.1.0.0.1.0.0.1

%e .0.0.1.0.0.1.1.1

%e .1.1.1.0.0.1.0.0

%e .1.0.0.1.0.0.1.1

%e .0.1.1.1.0.0.1.0

%e .0.1.0.0.0.1.1.0

%K nonn

%O 1,3

%A _R. H. Hardin_, Oct 26 2008