A001431 Number of graphs with n nodes and n-3 edges. (Formerly M1382 N0540)

0, 0, 1, 1, 2, 5, 10, 24, 63, 165, 467, 1405, 4435, 14775, 51814, 190443, 732472, 2939612, 12277230, 53233295, 239083372, 1109921554, 5316143531, 26225625392, 133050795412, 693227353094, 3704785464812

Offset

1,5

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.

Mathematica

(* first do *) Needs["Combinatorica`"] (* then *) Table[ NumberOfGraphs[n, n-3], {n, 3, 27}] (* Robert G. Wilson v *)

Crossrefs

Cf. A008406.

Sequence in context: A321007 A253013 A192471 * A324149 A054866 A242935

Adjacent sequences: A001428 A001429 A001430 * A001432 A001433 A001434

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from Vladeta Jovovic, Jan 12 2000

Status

approved