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A000717 Number of graphs with n nodes and floor(n(n-1)/4) edges.
(Formerly M2599 N1027)
3
1, 1, 1, 3, 6, 24, 148, 1646, 34040, 1358852, 106321628, 16006173014, 4525920859198, 2404130854745735, 2426376196165902704, 4648429222263945620900, 16788801124652327714275292, 114722035311851620271616102401 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

REFERENCES

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

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

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

LINKS

Sean A. Irvine, Table of n, a(n) for n = 1..40

M. L. Stein and P. R. Stein, Enumeration of Linear Graphs and Connected Linear Graphs up to p = 18 Points. Report LA-3775, Los Alamos Scientific Laboratory of the University of California, Los Alamos, NM, Oct 1967

CROSSREFS

Cf. A008406.

Sequence in context: A109155 A294381 A081072 * A076020 A018964 A018994

Adjacent sequences:  A000714 A000715 A000716 * A000718 A000719 A000720

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Sean A. Irvine, Mar 10 2011

STATUS

approved

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Last modified August 21 17:56 EDT 2018. Contains 313954 sequences. (Running on oeis4.)