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A162452 Number of reduced words of length n in the Weyl group D_46. 0
1, 46, 1080, 17250, 210794, 2101418, 17796503, 131648504, 868101374, 5182032940, 28344317261, 143450494506, 677150551521, 3001361428036, 12561988338047, 49889607533966, 188796675237026, 683282982630926, 2372613717733406 (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

N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche IV.)

J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.

LINKS

Table of n, a(n) for n=0..18.

FORMULA

G.f. for D_m is the polynomial f(n) * Product( f(2i), i=1..n-1 )/ f(1)^n, where f(k) = 1-x^k. Only finitely many terms are nonzero. This is a row of the triangle in A162206.

CROSSREFS

Sequence in context: A246993 A161691 A162186 * A010998 A004424 A258464

Adjacent sequences:  A162449 A162450 A162451 * A162453 A162454 A162455

KEYWORD

nonn

AUTHOR

John Cannon and N. J. A. Sloane, Dec 01 2009

STATUS

approved

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Last modified May 28 01:34 EDT 2020. Contains 334671 sequences. (Running on oeis4.)