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Number of simple disconnected perfect matching graphs on 2n nodes.
2

%I #4 May 29 2017 06:15:01

%S 0,1,6,116,10888

%N Number of simple disconnected perfect matching graphs on 2n nodes.

%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/PerfectMatching.html">Perfect Matching</a>

%F a(n) = A218462(n) - A218463(n).

%Y Cf. A218462 (simple not-necessarily connected perfect matching graphs).

%Y Cf. A218463 (connected perfect matching graphs).

%K nonn,more

%O 1,3

%A _Eric W. Weisstein_, May 29 2017