A161523 - OEIS

%I #5 Jul 19 2015 10:32:59

%S 1,23,275,2276,14650,78131,359214,1462801,5380529,18142125,56724395,

%T 165980490,457927079,1198603761,2991929700,7153857324,16447016616,

%U 36476745510,78265410550,162869776650,329453055975,649063995030

%N Number of reduced words of length n in the Weyl group A_23.

%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