OFFSET
1,2
COMMENTS
Number of trees on 2n labeled vertices containing no edges from a prescribed perfect matching. - Joel B. Lewis, Jun 20 2013
REFERENCES
Dragoš M. Cvetković, Michael Doob, Horst Sachs, Spectra of Graphs: Theory and Application, Academic Press, 1980.
LINKS
Takashi Horiyama, Masahiro Miyasaka, Riku Sasaki, Isomorphism Elimination by Zero-Suppressed Binary Decision Diagrams, 30th Canadian Conference on Computational Geometry, 2018. See Table 2.
Eric Weisstein's World of Mathematics, Cocktail Party Graph
Eric Weisstein's World of Mathematics, Spanning Tree
FORMULA
a(n) = n^(n-2) * (n-1)^n * 4^(n-1). [See "Spectra of graphs", p. 217; also observed by Joel B. Lewis, Jun 20 2013] - Andrey Zabolotskiy, Mar 18 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jul 16 2011
STATUS
approved