A146130 - OEIS

A146130

Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 3X2 zee 1,1 1,2 1,3 2,3 2,4 in any orientation.

%I #3 Mar 31 2012 12:35:09

%S 1,1,1,1,5,17,59,325,2193,20593,247017,3816169,76385445,1998729963,

%T 68606304143,3070344768595,178823377788539,13583194771026533,

%U 1345184891829774733

%N Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 3X2 zee 1,1 1,2 1,3 2,3 2,4 in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.1.1.1.0

%e .0.0.1.1.0.0.1.1

%e .0.1.0.1.1.1.0.0

%e .0.1.1.0.0.0.1.0

%e .1.0.1.0.0.0.1.0

%e .1.0.1.0.0.0.1.1

%e .1.1.0.1.1.1.0.1

%e .0.1.0.0.0.1.1.0

%K nonn

%O 1,5

%A _R. H. Hardin_, Oct 27 2008