A185349 Number of isomorphism classes of partially ordered sets of length n that occur as intervals in weak Bruhat order of some Coxeter group.

1, 1, 2, 6, 22, 93

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 A374544 A374545

Adjacent sequences: A185346 A185347 A185348 * A185350 A185351 A185352

Keyword

nonn,hard,more

Author

Matthew J. Samuel, Feb 15 2011

Status

approved