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A334247 Number of acyclic orientations of the edges of an n-dimensional cube. 3
1, 2, 14, 1862, 193270310, 47171704165698393638 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n) is the absolute value of the chromatic polynomial of the n-hypercube graph evaluated at -1.

LINKS

Table of n, a(n) for n=0..5.

David Eppstein, 14 acyclic orientations of a square

Eric Weisstein's World of Mathematics, Hypercube Graph

FORMULA

a(n) = Sum_{k=1..2^n} (-1)^(2^n-k) * k! * A334159(n, k). - Andrew Howroyd, Apr 21 2020

EXAMPLE

For n=2, there are 14 ways to orient the edges of a square without cycles (see links).

CROSSREFS

Cf. A334248 is the number of acyclic orientations with rotations and reflections of the same orientation excluded. A033815 is the analogous sequence for the n-dimensional cross-polytope (the dual of the n-cube).

Cf. A140986, A158348, A296914, A334159.

Sequence in context: A130421 A227403 A156736 * A277288 A296412 A296410

Adjacent sequences:  A334244 A334245 A334246 * A334248 A334249 A334250

KEYWORD

nonn,more

AUTHOR

Matthew Scroggs, Apr 20 2020

EXTENSIONS

a(5) from Andrew Howroyd, Apr 23 2020

STATUS

approved

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Last modified August 8 11:31 EDT 2020. Contains 336298 sequences. (Running on oeis4.)