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A006647 Number of graphs with n nodes, n-2 edges and no isolated vertices.
(Formerly M2586)
1

%I M2586 #16 Jun 05 2017 03:51:44

%S 1,1,3,6,15,33,83,202,527,1377,3744,10335,29297,84396,248034,740289,

%T 2245094,6904206,21522973,67936799,217026480,701159919,2289925258,

%U 7556363054,25184139149,84743377436,287815771822,986345040471,3409869008578

%N Number of graphs with n nodes, n-2 edges and no isolated vertices.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H W. L. Kocay, <a href="http://www.combinatorialmath.ca/G&amp;G/articles/algebraofsubgraphs.pdf">Some new methods in reconstruction theory</a>, pp. 89 - 114 of Combinatorial Mathematics IX. Proc. Ninth Australian Conference (Brisbane, August 1981). Ed. E. J. Billington, S. Oates-Williams and A. P. Street. Lecture Notes Math., 952. Springer-Verlag, 1982.

%F a(n) = A001430(n) - A001433(n - 1). - _Sean A. Irvine_, Jun 05 2017

%Y Cf. A001430, A001433.

%K nonn

%O 4,3

%A _N. J. A. Sloane_.

%E More terms from _Vladeta Jovovic_, Mar 02 2008

%E More terms from _Sean A. Irvine_, Jun 05 2017

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Last modified June 6 23:38 EDT 2024. Contains 373136 sequences. (Running on oeis4.)