%I #6 Mar 09 2015 00:18:00
%S 1,2,1,11,7,195,85,8969,3573,1232795,391285,471487297,125714303,
%T 516844071813,113185189874,1603508113421239,290842806833709,
%U 14148460147460008963,2118392163856080466,354360105981877906958557
%N Number of n X n binary matrices, symmetric under horizontal and vertical reflection, with no more than 2 ones in any 2 X 2 subblock.
%H R. H. Hardin, <a href="/A141504/b141504.txt">Table of n, a(n) for n = 0..30</a>
%K nonn
%O 0,2
%A _R. H. Hardin_, Aug 10 2008
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