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A001434 Number of graphs with n nodes and n edges.
(Formerly M1653 N0647)

%I M1653 N0647

%S 0,0,1,2,6,21,65,221,771,2769,10250,39243,154658,628635,2632420,

%T 11353457,50411413,230341716,1082481189,5228952960,25945377057,

%U 132140242356,690238318754,3694876952577

%N Number of graphs with n nodes and n edges.

%D J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 146.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

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

%H Sean A. Irvine, <a href="/A001434/b001434.txt">Table of n, a(n) for n = 1..40</a>

%H CombOS - Combinatorial Object Server, <a href="http://combos.org/nauty">generate graphs</a>

%H M. L. Stein and P. R. Stein, <a href="http://dx.doi.org/10.2172/4180737">Enumeration of Linear Graphs and Connected Linear Graphs up to p = 18 Points</a>. Report LA-3775, Los Alamos Scientific Laboratory of the University of California, Los Alamos, NM, Oct 1967.

%t (* first do *) Needs["Combinatorica`"] (* then *) Table[ NumberOfGraphs[n, n], {n, 24}] (* _Robert G. Wilson v_, Mar 22 2011 *)

%Y Cf. A008406.

%K nonn,easy,nice

%O 1,4

%A _N. J. A. Sloane_.

%E More terms from _Vladeta Jovovic_, Jan 07 2000

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Last modified August 8 19:29 EDT 2020. Contains 336298 sequences. (Running on oeis4.)