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A162413 Number of reduced words of length n in the Weyl group D_44. 49
1, 44, 989, 15136, 177374, 1697080, 13804461, 98156916, 622600869, 3577478696, 18848352755, 91943892924, 418593879770, 1790510819500, 7236416033496, 27766992285908, 101579448507141, 355579239690840, 1194844427708580 (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
N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche IV.)
J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.
LINKS
FORMULA
G.f. for D_m is the polynomial f(n) * Product( f(2i), i=1..n-1 )/ f(1)^n, where f(k) = 1-x^k. Only finitely many terms are nonzero. This is a row of the triangle in A162206.
CROSSREFS
Sequence in context: A035611 A161679 A162182 * A010996 A295251 A295650
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 01 2009
STATUS
approved

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Last modified May 22 09:32 EDT 2024. Contains 372745 sequences. (Running on oeis4.)