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

Author

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

Keywords

• nonn

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.)

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.