A146284 - OEIS

A146284

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 111-110-111 pattern in any orientation.

%I #4 Mar 31 2012 12:35:10

%S 1,1,1,1,1,1,1,1,5,9,17,25,55,133,419,1009,4455,14333,61219,207501,

%T 982915,4258653,26235061,130258871,1014665059,6176852821

%N Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 111-110-111 pattern in any orientation.

%e Maximal 9 X 9 example

%e .0.0.0.1.0.1.0.0.0

%e .0.0.0.1.1.1.0.0.0

%e .1.1.1.0.0.0.1.1.1

%e .0.1.1.0.0.0.1.1.0

%e .1.1.1.0.0.0.1.1.1

%e .0.0.0.1.1.1.0.0.0

%e .0.0.0.1.0.1.0.0.0

%K nonn

%O 1,9

%A _R. H. Hardin_