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A185349 Number of isomorphism classes of partially ordered sets of length n that occur as intervals in weak Bruhat order of some Coxeter group. 0
1, 1, 2, 6, 22, 93 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

Björner, Anders; Brenti, Francesco. Combinatorics of Coxeter groups. Graduate Texts in Mathematics, 231. Springer, New York, 2005.

LINKS

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

Matthew J. Samuel, Word posets, complexity, and Coxeter groups, arXiv:1101.4655 [math.CO]

Matthew J. Samuel, Enumeration of small weak order intervals

CROSSREFS

a(n) >= A000112(n).

Sequence in context: A091768 A229741 A261518 * A317652 A150274 A109317

Adjacent sequences:  A185346 A185347 A185348 * A185350 A185351 A185352

KEYWORD

nonn,hard,more

AUTHOR

Matthew J. Samuel, Feb 15 2011

STATUS

approved

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Last modified December 4 12:33 EST 2020. Contains 338923 sequences. (Running on oeis4.)