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%I #17 Jan 16 2022 17:46:47
%S 0,0,0,2,13,93,809,11005,260793,11715808,1006698524,164059824899,
%T 50335907853919,29003487462805642,31397381142761123838,
%U 63969560113225175845492,245871831682084026518599099,1787331725248899088890197955308,24636021429399867655322650752269938
%N Number of connected graphs on n unlabeled nodes that contain at least two cycles.
%C Original name: number of unlabeled complex components with n nodes.
%C We can find in "The Birth of the Giant Component", p. 2, see the first link:
%C "As each of the random graphs evolved, the story went, never once was there more than a single 'complex' component; i.e. there never were two or more components present simultaneously that were neither trees nor unicyclic."
%C So a complex component is a connected graph that is neither a tree nor an unicyclic graph.
%H Andrew Howroyd, <a href="/A140636/b140636.txt">Table of n, a(n) for n = 1..50</a>
%H Svante Janson, Donald E. Knuth, Tomasz Luczak and Boris Pittel, <a href="http://www.math.uu.se/~svante/papers/index.html">The Birth of the Giant Component</a>, <a href="http://dx.doi.org/ 10.1002/rsa.3240040303">[DOI]</a>, Rand. Struct. Alg. 4 (3) (1993) 233-358
%H N. J. A. Sloane, <a href="/A000088/a000088.gif">Illustration of initial terms of A001349</a>.
%F a(n) = A001349(n) - A005703(n).
%F a(n) = A001349(n) - A000055(n) - A001429(n).
%e a(4) = 2. See the two complex components with 4 nodes in the Sloane illustration.
%Y The labeled version is A140638.
%Y Cf. A001349, A000055, A001429, A005703.
%K nonn
%O 1,4
%A _Washington Bomfim_, May 20 2008
%E Name changed by _Andrew Howroyd_, Jan 16 2022
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