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A161987 Number of reduced words of length n in the Weyl group B_32. 0
1, 32, 527, 5952, 51831, 370976, 2271896, 12237280, 59146604, 260441632, 1057250877, 3994502272, 14156055636, 47361532160, 150411609649, 455543049760, 1321024921186, 3680779823776, 9884216117666, 25650056954016 (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..19.

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: A125489 A084486 A161640 * A162379 A162739 A010984

Adjacent sequences: A161984 A161985 A161986 * A161988 A161989 A161990

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified December 6 11:30 EST 2022. Contains 358631 sequences. (Running on oeis4.)