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 A161662 Number of reduced words of length n in the Weyl group A_41. 0
 1, 41, 860, 12299, 134848, 1208516, 9217866, 61521649, 366624707, 1980976460, 9822684102, 45131469838, 193676694825, 781450953227, 2981168796829, 10804753100301, 37358311880918, 123672795559348, 393238376839063 (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 PoincarĂ© polynomial. N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche I.) LINKS FORMULA G.f. for A_m is the polynomial Prod_{k=1..m}(1-x^(k+1))/(1-x). Only finitely many terms are nonzero. This is a row of the triangle in A008302. CROSSREFS Sequence in context: A087856 A010957 A299332 * A162178 A162403 A010993 Adjacent sequences:  A161659 A161660 A161661 * A161663 A161664 A161665 KEYWORD nonn AUTHOR John Cannon and N. J. A. Sloane, Nov 30 2009 STATUS approved

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Last modified September 22 19:01 EDT 2018. Contains 315270 sequences. (Running on oeis4.)