A048193 Number of chordal graphs (or triangulated graphs) on n vertices.

1, 2, 4, 10, 27, 94, 393, 2119, 14524, 126758, 1392387, 19109099, 326005775, 6905776799, 181945055235

Offset: 1

Author

Gordon F. Royle

Keywords

• nonn
• more

Comments

Graphs having no induced cycles of any length > 3, so every cycle in the graph has a chord, or is "triangulated".

All such graphs are perfect.

Euler transform of A048192. - Eric M. Schmidt, Mar 25 2015

Conjectured partial sums of A079456. - Sean A. Irvine, Jun 25 2022

Links

• S. Hougardy, Home Page
• S. Hougardy, Classes of perfect graphs, Discr. Math. 306 (2006), 2529-2571.
• Eric Weisstein's World of Mathematics, Chordal Graph

Crossrefs

Cf. A048192 (connected chordal graphs).

Cf. A287427 (disconnected chordal graphs).

Cf. A048194.

Formula

a(n) = A048192(n) + A287427(n).

Extensions

Edited by N. J. A. Sloane, Jul 04 2008

a(12) added (using A048192) by Eric M. Schmidt, Mar 25 2015

a(13) and a(14) added (using A048192) by Falk Hüffner, Jan 15 2016

a(15) added (using A048192) by Jakub Jablonski, Sep 15 2020