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 A146009 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation. 0

%I #3 Mar 31 2012 12:35:08

%S 1,1,1,1,3,9,22,75,380,2417,17011,150387,1725197,24767029,439881987,

%T 9753623996,269467512241,9272282447537,399403152426578,

%U 21537582386961680,1447800106086744192,121198502960515093107

%N Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation.

%e Maximal 8 X 8 example

%e .0.0.1.1.1.0.0.0

%e .0.0.0.1.0.0.0.0

%e .1.0.0.1.0.0.0.0

%e .1.1.1.0.0.0.0.1

%e .1.0.0.0.0.1.1.1

%e .0.0.0.0.1.0.0.1

%e .0.0.0.0.1.0.0.0

%e .0.0.0.1.1.1.0.0

%K nonn

%O 1,5

%A _R. H. Hardin_, Oct 26 2008

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Last modified December 10 19:02 EST 2023. Contains 367717 sequences. (Running on oeis4.)