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%I #4 Mar 31 2012 20:01:59
%S 1,4,32,496,14172,816684,87982904
%N Number of symmetric singular n X n (0,1) matrices over the reals.
%C _W. Edwin Clark_ computed the first entries.
%F a(n) = 2^(n*(n+1)/2) - A086899(n).
%Y Cf. A046747, A086899, A086879, A118989.
%K nonn
%O 1,2
%A Yuval Dekel (dekelyuval(AT)hotmail.com), Sep 19 2003
%E a(6) and a(7) from _Giovanni Resta_, May 08 2006
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