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Number of simple disconnected integral graphs on n vertices.
2

%I #8 Dec 29 2022 15:12:07

%S 0,1,2,4,7,14,26,49,97,186,379

%N Number of simple disconnected integral graphs on n vertices.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DisconnectedGraph.html">Disconnected Graph</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/IntegralGraph.html">Integral Graph</a>

%F a(n) = A077027(n) - A064731(n).

%Y Cf. A077027 (number of simple not necessarily connected integral graphs).

%Y Cf. A064731 (number of simple connected integral graphs).

%K nonn,more

%O 1,3

%A _Eric W. Weisstein_, May 20 2017