The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A162297 Number of reduced words of length n in the Weyl group D_12. 10
 1, 12, 77, 352, 1286, 3992, 10933, 27092, 61841, 131768, 264759, 505660, 923857, 1623104, 2753895, 4528612, 7239585, 11280072, 17168009, 25572196, 37340381, 53528488, 75430016, 104604424, 142903123, 192491532, 255865533, 335860592 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 REFERENCES N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10a, page 231, W(t). J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial. LINKS FORMULA The growth series for the finite Coxeter group of type D_k (k >= 3) has G.f. = Prod_i (1-x^{m_i})/(1-x) where the m_i are [1,3,5,...,2k-3,k-1]. MATHEMATICA n = 12; x = y + y O[y]^(n^2); (1-x^n) Product[1-x^(2k), {k, 1, n-1}]/(1-x)^n // CoefficientList[#, y]& (* Jean-François Alcover, Mar 25 2020, from A162206 *) PROG Computed with MAGMA using commands similar to those used to compute A161409. CROSSREFS The growth series for D_k, k >= 5, are A162208-A162212, A162248, A162288, A162297. The growth series for D_k, k >= 3, are also the rows of the triangle A162206. Sequence in context: A335253 A071767 A161461 * A161858 A054334 A267174 Adjacent sequences:  A162294 A162295 A162296 * A162298 A162299 A162300 KEYWORD nonn AUTHOR John Cannon and N. J. A. Sloane, Dec 01 2009 EXTENSIONS Entry revised by N. J. A. Sloane, Jan 17 2016 STATUS approved

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

Last modified June 6 03:48 EDT 2020. Contains 334858 sequences. (Running on oeis4.)