A161526 - OEIS

%I #5 Jul 19 2015 10:32:27

%S 1,26,350,3249,23373,138853,708903,3196324,12981645,48206991,

%T 165596757,531131433,1602738098,4579020513,12451908378,32375259017,

%U 80796089046,194191143975,450825834354,1013569936833,2211876507387,4694809541046

%N Number of reduced words of length n in the Weyl group A_26.

%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 I.)

%F 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.

%K nonn

%O 0,2

%A _John Cannon_ and _N. J. A. Sloane_, Nov 30 2009