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A162181 Number of reduced words of length n in the Weyl group B_43. 0
1, 43, 945, 14147, 162238, 1519706, 12107381, 84352455, 524443953, 2954877827, 15270874059, 73095540169, 326649986846, 1371916939730, 5445905213996, 20530576252412, 73812456221233, 253999791183699, 839265188017740 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Computed with MAGMA using commands similar to those used to compute A161409.
REFERENCES
J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.
N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche II.)
LINKS
FORMULA
G.f. for B_m is the polynomial Prod_{k=1..m}(1-x^(2k))/(1-x). Only finitely many terms are nonzero. This is a row of the triangle in A128084.
CROSSREFS
Sequence in context: A157722 A010959 A161668 * A162412 A010995 A253915
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Nov 30 2009
STATUS
approved

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Last modified April 22 06:25 EDT 2024. Contains 371887 sequences. (Running on oeis4.)