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A267385
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Number of acyclic orientations of the Turán graph T(n,5).
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2
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1, 1, 2, 6, 24, 120, 600, 3720, 27240, 229080, 2170680, 20452440, 217008600, 2550317880, 32808887160, 457907248920, 6355848354360, 95721761831160, 1551458493435480, 26890032710452440, 495810323060597880, 9097662007250393880, 177624183228083188440
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OFFSET
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0,3
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COMMENTS
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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.
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LINKS
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FORMULA
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a(n) ~ n! / (4 * (1 - log(5/4))^2 * 5^n * (log(5/4))^(n+1)). - Vaclav Kotesovec, Feb 18 2017
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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