A048180 Number of graphs with n nodes and n+2 edges.

1, 4, 24, 131, 663, 3252, 15772, 75415, 359307, 1711908, 8191607, 39500169, 192525021, 950868860, 4769060224, 24331970791, 126457607026, 670143402073, 3623530476832, 19998343352758, 112668088476243, 647904733883526

Offset: 4

Author

N. J. A. Sloane

Keywords

• nonn
• easy

References

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

Links

• Sean A. Irvine, Table of n, a(n) for n = 4..36
• 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.

Extensions

More terms from Vladeta Jovovic, Jan 03 2000

More terms from Sean A. Irvine, Jun 07 2017