A161649 - OEIS

%I #5 Jul 19 2015 10:30:53

%S 1,36,665,8399,81548,648870,4405035,26229634,139771903,676798487,

%T 3013713196,12459957237,48208023941,175693594055,606498724614,

%U 1992486365264,6254976819720,18830657260788,54534379879411

%N Number of reduced words of length n in the Weyl group A_36.

%C Computed with MAGMA using commands similar to those used to compute A161409.

%D N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche I.)

%D J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.

%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