cp's OEIS Frontend

A169460 Number of reduced words of length n in Coxeter group on 15 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.

%I A169460 #6 Nov 26 2016 07:19:54
%S A169460 1,15,210,2940,41160,576240,8067360,112943040,1581202560,22136835840,
%T A169460 309915701760,4338819824640,60743477544960,850408685629440,
%U A169460 11905721598812160,166680102383370240,2333521433367183360
%N A169460 Number of reduced words of length n in Coxeter group on 15 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.
%C A169460 The initial terms coincide with those of A170734, although the two sequences are eventually different.
%C A169460 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169460 <a href="/index/Rec#order_33">Index entries for linear recurrences with constant coefficients</a>, signature (13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, -91).
%F A169460 G.f. (t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 +
%F A169460 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 +
%F A169460 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 +
%F A169460 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t +
%F A169460 1)/(91*t^33 - 13*t^32 - 13*t^31 - 13*t^30 - 13*t^29 - 13*t^28 - 13*t^27
%F A169460 - 13*t^26 - 13*t^25 - 13*t^24 - 13*t^23 - 13*t^22 - 13*t^21 - 13*t^20 -
%F A169460 13*t^19 - 13*t^18 - 13*t^17 - 13*t^16 - 13*t^15 - 13*t^14 - 13*t^13 -
%F A169460 13*t^12 - 13*t^11 - 13*t^10 - 13*t^9 - 13*t^8 - 13*t^7 - 13*t^6 - 13*t^5
%F A169460 - 13*t^4 - 13*t^3 - 13*t^2 - 13*t + 1)
%K A169460 nonn
%O A169460 0,2
%A A169460 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009