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A162205 Number of reduced words of length n in the Weyl group B_50. 0
1, 50, 1274, 22050, 291549, 3140360, 28695575, 228732790, 1623128975, 10413794040, 61146955156, 331819334000, 1677578203770, 7954932265700, 35582378559071, 150868021657130, 608916641370150, 2348116000139330 (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

Table of n, a(n) for n=0..17.

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: A187459 A035720 A161695 * A162492 A017713 A283311

Adjacent sequences:  A162202 A162203 A162204 * A162206 A162207 A162208

KEYWORD

nonn

AUTHOR

John Cannon and N. J. A. Sloane, Nov 30 2009

STATUS

approved

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Last modified October 22 08:00 EDT 2019. Contains 328315 sequences. (Running on oeis4.)