A006650 Number of graphs with n nodes, n+1 edges and no isolated vertices. (Formerly M3903)

1, 5, 20, 73, 271, 974, 3507, 12487, 44475, 157814, 559952, 1985053, 7040855, 24986930, 88782435, 315911844, 1126178655, 4023135764, 14406870196, 51728509807, 186275015554, 672886200335

Offset

4,2

References

W. L. Kocay, Some new methods in reconstruction theory, 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.

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

Links

Table of n, a(n) for n=4..25.

Crossrefs

Cf. A048179, A048180.

Sequence in context: A118049 A114247 A272086 * A034535 A316222 A273718

Adjacent sequences: A006647 A006648 A006649 * A006651 A006652 A006653

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Vladeta Jovovic, Mar 02 2008

Status

approved