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A373456
Number of tree interval posets of permutations of size n, considered up to isomorphism.
1
1, 1, 1, 3, 6, 14, 32, 79, 192, 488, 1244, 3240, 8497, 22561, 60309, 162541, 440598, 1201377, 3291426, 9058464, 25027797, 69401101, 193071153, 538724060, 1507288378, 4227824974, 11886150870, 33488522111, 94539554742, 267383598840, 757539956852, 2149698586706, 6109515731611
OFFSET
1,4
COMMENTS
See Remark 24 in [Bouvel-Cioni-Izart].
REFERENCES
Bridget E. Tenner. Interval Posets of Permutations. Order, 39(3):523-536, 2022.
LINKS
Mathilde Bouvel, Lapo Cioni, and Benjamin Izart, The interval posets of permutations seen from the decomposition tree perspective, arXiv:2110.10000 [math.CO], 2021-2024.
Bridget E. Tenner, Interval Posets for Permutations, arXiv:2007.06142 [math.CO], 2020-2021.
FORMULA
Asymptotic behavior of a(n) is c*n^(-3/2)*r^n with c approximately 0.2597 and r approximately 2.9784. See M. Bouvel, L. Cioni, B. Izart (Remark 24).
CROSSREFS
For the same posets but not considered up to isomorphism, see A054515.
For interval posets that are not necessarily trees, see A373455 (for posets also considered up to isomorphism) and A348479 (otherwise).
Sequence in context: A238768 A272362 A182905 * A330053 A192678 A114945
KEYWORD
nonn
AUTHOR
Mathilde Bouvel, Jun 06 2024
STATUS
approved