%I A086906
%S A086906 1,4,32,496,14172,816684,87982904
%N A086906 Number of symmetric singular n X n (0,1) matrices over the reals.
%C A086906 Edwin Clark (eclark(AT)math.usf.edu) computed the first entries.
%F A086906 a(n) = 2^(n*(n+1)/2) - A086899(n).
%Y A086906 Cf. A046747, A086899, A086879, A118989.
%Y A086906 Sequence in context: A005121 A037964 A089285 this_sequence A034663 A093581 
               A102557
%Y A086906 Adjacent sequences: A086903 A086904 A086905 this_sequence A086907 A086908 
               A086909
%K A086906 nonn
%O A086906 1,2
%A A086906 Yuval Dekel (dekelyuval(AT)hotmail.com), Sep 19 2003
%E A086906 a(6) and a(7) from Giovanni Resta (g.resta(AT)iit.cnr.it), May 08 2006