A145954 - OEIS

A145954

Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a zee 1,1 1,2 2,2 2,3 in any orientation.

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

%S 1,1,1,1,1,1,9,9,33,33,333,333,7127,7127,205501,205501,11166945,

%T 11166945,1122739259,1122739259,190153543115,190153543115,

%U 56969419979245,56969419979245,30406497496961445,30406497496961445

%N Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a zee 1,1 1,2 2,2 2,3 in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.0.0.0.0

%e .1.1.0.0.0.0.1.1

%e .0.1.1.0.0.1.1.0

%e .0.0.0.0.0.0.0.0

%e .0.1.1.0.0.1.1.0

%e .1.1.0.0.0.0.1.1

%e .0.0.0.0.0.0.0.0

%K nonn

%O 1,7

%A _R. H. Hardin_, Oct 25 2008