A162149 Number of reduced words of length n in the Weyl group B_35.

1, 35, 629, 7735, 73184, 567952, 3763935, 21898413, 114117990, 540864298, 2359388214, 9564192010, 36311331322, 129962338310, 440928822623, 1424753834021, 4402462293690, 13054834025406, 37266085146835

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..18.

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: A010951 A033281 A161648 * A162384 A126925 A010987

Adjacent sequences: A162146 A162147 A162148 * A162150 A162151 A162152

Keyword

nonn

Author

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

Status

approved