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%I #8 Mar 09 2015 04:29:29
%S 1,1,2,9,34,730,4376,905345,10601986,10009765626,200097656252,
%T 2177748514672962,85812416258106784,4142789042980129347156,
%U 289904403212517959978240,175519033940460517461369847809
%N Half the number of n X n binary matrices, symmetric under horizontal reflection, having equal row sums.
%H R. H. Hardin, Jul 28 2008, <a href="/A140217/b140217.txt">Table of n, a(n) for n = 1..25</a>
%K nonn
%O 1,3
%A _R. H. Hardin_, Jul 28 2008