A147409 - OEIS

A147409

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1001-1001-1111 pattern in any orientation.

%I #8 Sep 09 2025 03:41:01

%S 1,1,1,1,1,1,1,1,1,3,7,13,21,31,61,147,365,1043,3041,10027,33377,

%T 115807,406723,1580475,6700609

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1001-1001-1111 pattern in any orientation.

%e Maximal 10 X 10 example

%e .0.0.0.1.0.0.1.0.0.0

%e .0.0.0.1.1.1.1.0.0.0

%e .1.1.1.0.0.0.0.1.1.1

%e .0.0.1.0.0.0.0.1.0.0

%e .1.1.1.0.0.0.0.1.1.1

%e .0.0.0.1.1.1.1.0.0.0

%e .0.0.0.1.0.0.1.0.0.0

%K nonn,more

%O 1,10

%A _R. H. Hardin_