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A281723 Smallest positive integer that cannot be obtained as the number of linear extensions of a poset of size n. 1
2, 2, 3, 4, 7, 13, 17, 59, 253, 979 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
a(n) is the smallest positive integer such that A160371(a(n)) > n.
LINKS
Swee Hong Chan and Igor Pak, Computational complexity of counting coincidences, arXiv:2308.10214 [math.CO], 2023. See p. 12.
Swee Hong Chan and Igor Pak, Linear extensions and continued fractions, arXiv:2401.09723 [math.CO], 2024.
EXAMPLE
a(8) = 253, so the number 253 cannot be obtained as the number of linear extensions of a poset of size 8, but every integer from 1 to 252 can.
CROSSREFS
Cf. A160371.
Sequence in context: A051920 A286350 A023105 * A011784 A302487 A032252
KEYWORD
nonn,hard,more
AUTHOR
François Labelle, Jan 28 2017
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)