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 A048193 Number of chordal graphs (or triangulated graphs) on n vertices. 4
 1, 2, 4, 10, 27, 94, 393, 2119, 14524, 126758, 1392387, 19109099, 326005775, 6905776799, 181945055235 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 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 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 FORMULA a(n) = A048192(n) + A287427(n). CROSSREFS Cf. A048192 (connected chordal graphs). Cf. A287427 (disconnected chordal graphs). Cf. A048194. Sequence in context: A268522 A123428 A005975 * A123411 A278418 A321946 Adjacent sequences:  A048190 A048191 A048192 * A048194 A048195 A048196 KEYWORD nonn,more,changed AUTHOR 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 STATUS approved

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Last modified September 24 06:24 EDT 2020. Contains 337317 sequences. (Running on oeis4.)