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%I #5 Jul 19 2015 10:24:34
%S 1,28,405,4032,31058,197288,1075697,5174180,22396787,88562288,
%T 323686749,1103799420,3538931886,10735761372,30981056614,85436083852,
%U 226032307036,575653531156,1415485760287,3369314791024,7781762472652,17474847498496
%N Number of reduced words of length n in the Weyl group B_28.
%C Computed with MAGMA using commands similar to those used to compute A161409.
%D J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.
%D N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche II.)
%F 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.
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Nov 30 2009
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