A147166 - OEIS

A147166

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1101-0111 pattern in any orientation.

%I #4 Mar 31 2012 12:35:15

%S 1,1,1,1,1,1,1,1,5,13,25,47,123,369,1165,4187,18445,79415,399577,

%T 2091817,12535539,80500731

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1101-0111 pattern in any orientation.

%e Maximal 9 X 9 example

%e .0.0.0.0.0.0.1.0.0

%e .0.0.0.1.0.1.1.0.0

%e .0.0.0.1.1.1.0.1.1

%e .0.1.1.0.0.0.1.1.0

%e .0.0.1.0.0.0.1.0.0

%e .0.1.1.0.0.0.1.1.0

%e .1.1.0.1.1.1.0.0.0

%e .0.0.1.1.0.1.0.0.0

%e .0.0.1.0.0.0.0.0.0

%K nonn

%O 1,9

%A _R. H. Hardin_, Nov 04 2008