# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a162328 Showing 1-1 of 1 %I A162328 #9 Feb 21 2024 11:31:54 %S A162328 1,17,152,952,4691,19363,69615,223839,656013,1777469,4501652,10749780, %T A162328 24374702,52784014,109694031,219658751,425310726,798645125,1458198664, %U A162328 2594648817,4508215686,7662320971,12759278753,20845394645,33454765680 %N A162328 Number of reduced words of length n in the Weyl group D_17. %D A162328 N. Bourbaki, Groupes et alg. de Lie, Chap. 4, 5, 6. (The group is defined in Planche IV.) %D A162328 J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial. %H A162328 Index entries for growth series for groups %F A162328 The growth series for D_k is the polynomial f(k)*Prod_{i=1..k-1} f(2*i), where f(m) = (1-x^m)/(1-x) [Corrected by _N. J. A. Sloane_, Aug 07 2021]. This is a row of the triangle in A162206. %p A162328 # Growth series for D_k, truncated to terms of order M. - _N. J. A. Sloane_, Aug 07 2021 %p A162328 f := proc(m::integer) (1-x^m)/(1-x) ; end proc: %p A162328 g := proc(k,M) local a,i; global f; %p A162328 a:=f(k)*mul(f(2*i),i=1..k-1); %p A162328 seriestolist(series(a,x,M+1)); %p A162328 end proc; %Y A162328 Growth series for groups D_n, n = 3,...,50: A161435, A162207, A162208, A162209, A162210, A162211, A162212, A162248, A162288, A162297, A162300, A162301, A162321, A162327, A162328, A162346, A162347, A162359, A162360, A162364, A162365, A162366, A162367, A162368, A162369, A162370, A162376, A162377, A162378, A162379, A162380, A162381, A162384, A162388, A162389, A162392, A162399, A162402, A162403, A162411, A162412, A162413, A162418, A162452, A162456, A162461, A162469, A162492; also A162206. %K A162328 nonn %O A162328 0,2 %A A162328 _John Cannon_ and _N. J. A. Sloane_, Dec 01 2009 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE