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A161526
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Number of reduced words of length n in the Weyl group A_26.
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0
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1, 26, 350, 3249, 23373, 138853, 708903, 3196324, 12981645, 48206991, 165596757, 531131433, 1602738098, 4579020513, 12451908378, 32375259017, 80796089046, 194191143975, 450825834354, 1013569936833, 2211876507387, 4694809541046
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Computed with MAGMA using commands similar to those used to compute A161409.
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REFERENCES
| J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincare polynomial.
N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche I.)
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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.
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CROSSREFS
| Sequence in context: A042306 A053494 A054938 * A161933 A162368 A162718
Adjacent sequences: A161523 A161524 A161525 * A161527 A161528 A161529
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KEYWORD
| nonn
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AUTHOR
| John Cannon (john(AT)maths.usyd.edu.au) and N. J. A. Sloane (njas(AT)research.att.com), Nov 30 2009
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