

A267390


Number of acyclic orientations of the Turán graph T(n,10).


2



1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 36288000, 402796800, 4906137600, 64988179200, 929459059200, 14266826784000, 233845982899200, 4075249496774400, 75225258805132800, 1465957162768492800, 28530213421847558400, 586170618419794464000
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OFFSET

0,3


COMMENTS

An acyclic orientation is an assignment of a direction to each edge such that no cycle in the graph is consistently oriented. Stanley showed that the number of acyclic orientations of a graph G is equal to the absolute value of the chromatic polynomial X_G(q) evaluated at q=1.


LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..450
Richard P. Stanley, Acyclic Orientations of Graphs, Discrete Mathematics, 5 (1973), pages 171178, doi:10.1016/0012365X(73)901088
Wikipedia, Turán graph


FORMULA

a(n) ~ n! / (9 * (1  log(10/9))^(9/2) * 10^n * (log(10/9))^(n+1)).  Vaclav Kotesovec, Feb 18 2017


CROSSREFS

Column k=10 of A267383.
Sequence in context: A173850 A154658 A179369 * A193937 A072167 A230233
Adjacent sequences: A267387 A267388 A267389 * A267391 A267392 A267393


KEYWORD

nonn


AUTHOR

Alois P. Heinz, Jan 13 2016


STATUS

approved



