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URL: https://oeis.org/A000717

⇱ A000717 - OEIS

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A000717
Number of graphs with n nodes and floor(n(n-1)/4) edges.
6
1, 1, 1, 3, 6, 24, 148, 1646, 34040, 1358852, 106321628, 16006173014, 4525920859198, 2404130854745735, 2426376196165902704, 4648429222263945620900, 16788801124652327714275292, 114722035311851620271616102401
OFFSET
1,4
COMMENTS
This is the largest number of graphs with n vertices that all have the same number of edges. a(n) <= A371161(n). - Allan Bickle, Apr 18 2024
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
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
EXAMPLE
There are three graphs with 4 vertices and 3 edges, K_3 U K_1, K_{1,3}, and P_4, so a(4) = 3. - Allan Bickle, Apr 18 2024
CROSSREFS
Sequence in context: A294381 A374654 A081072 * A076020 A018994 A018964
KEYWORD
nonn,nice
EXTENSIONS
More terms from Sean A. Irvine, Mar 10 2011
STATUS
approved