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%I #11 Aug 14 2019 22:16:24
%S 0,0,0,0,1,8,138,3459,137912,8735904,903185866,159235673397,
%T 50091451190693
%N Number of simple imperfect graphs on n vertices.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ImperfectGraph.html">Imperfect Graph.</a>
%F a(n) = A000088(n) - A052431(n).
%Y Cf. A000088, A052431, A187237.
%K nonn,more,hard
%O 1,6
%A _Eric W. Weisstein_, Mar 07 2011
%E a(13) from _Alois P. Heinz_, Aug 14 2019