A145998 - OEIS

A145998

Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 3X3 plus 2,1 2,2 2,3 1,2 3,2.

%I #3 Mar 31 2012 12:35:08

%S 1,1,2,1,4,1,27,10,325,79,7166,1068,296998,32561,25489453,2049805,

%T 4199698432,237788014,1353419597835,53948164143,849049576212123,

%U 24026619761999,1041648115351377356,20926733702956682

%N Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 3X3 plus 2,1 2,2 2,3 1,2 3,2.

%e Maximal 8 X 8 example

%e .0.1.0.0.0.0.1.0

%e .1.1.1.0.0.1.1.1

%e .0.1.0.0.0.0.1.0

%e .0.0.0.0.0.0.0.0

%e .0.1.0.0.0.0.1.0

%e .1.1.1.0.0.1.1.1

%e .0.1.0.0.0.0.1.0

%K nonn

%O 1,3

%A _R. H. Hardin_, Oct 26 2008