%I #11 Dec 06 2018 04:38:57

%S 1,1,2,1,2,1,5,2,9,3,28,6,76,13,295,41,1196,134,6337,523,36933,2341,

%T 266568,13112,2186885,85330,21909179,657274,253725200,5867785

%N Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only in a 3 X 3 "plus" shape (e.g., consisting of the points at the coordinates (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 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,more

%O 1,3

%A _R. H. Hardin_, Oct 26 2008