The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A161876 Number of reduced words of length n in the Weyl group B_16. 1
 1, 16, 135, 800, 3739, 14672, 50252, 154224, 432174, 1121456, 2724183, 6248128, 13624922, 28409312, 56910017, 109964720, 205651975, 373334400, 659553555, 1136450288, 1913567669, 3154109024, 5096972454, 8086166144, 12609525259 (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 Robert Israel, Table of n, a(n) for n = 0..256 (complete sequence) 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. MAPLE G:= normal(mul((1-x^(2*k))/(1-x), k=1..16)): seq(coeff(G, x, j), j=0..256); # Robert Israel, Mar 31 2017 CROSSREFS Sequence in context: A284338 A161477 A162327 * A110274 A067814 A219904 Adjacent sequences: A161873 A161874 A161875 * A161877 A161878 A161879 KEYWORD nonn,fini,full AUTHOR John Cannon and N. J. A. Sloane, Nov 30 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 24 05:54 EST 2024. Contains 370294 sequences. (Running on oeis4.)