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%I #12 Jun 09 2021 02:31:08
%S 1,2,6,20,90,544,5096,79220,2208158,113737744,10926144928
%N Sum over all unlabeled graphs of order n, of the number of graphs obtainable by deletion of a single vertex in the graph.
%C For a graph G with n vertices, consider deleting each vertex in turn (along with any associated edges). The resulting graphs will have n-1 vertices. Count the distinct graphs reached. This sequence gives the sum of this count over all graphs with n vertices.
%H Sean A. Irvine, <a href="/A336544/a336544.pdf">Illustration of initial terms</a>
%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a336/A336544.java">Java program</a> (github)
%Y Cf. A336545 (connected graphs).
%K nonn,more
%O 1,2
%A _Sean A. Irvine_, Jul 25 2020
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