cp's OEIS Frontend

A169516 Number of reduced words of length n in Coxeter group on 23 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.

%I A169516 #6 Nov 26 2016 07:35:59
%S A169516 1,23,506,11132,244904,5387888,118533536,2607737792,57370231424,
%T A169516 1262145091328,27767192009216,610878224202752,13439320932460544,
%U A169516 295665060514131968,6504631331310903296,143101889288839872512
%N A169516 Number of reduced words of length n in Coxeter group on 23 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.
%C A169516 The initial terms coincide with those of A170742, although the two sequences are eventually different.
%C A169516 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169516 <a href="/index/Rec#order_34">Index entries for linear recurrences with constant coefficients</a>, signature (21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, -231).
%F A169516 G.f. (t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 +
%F A169516 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 +
%F A169516 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 +
%F A169516 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 +
%F A169516 2*t + 1)/(231*t^34 - 21*t^33 - 21*t^32 - 21*t^31 - 21*t^30 - 21*t^29 -
%F A169516 21*t^28 - 21*t^27 - 21*t^26 - 21*t^25 - 21*t^24 - 21*t^23 - 21*t^22 -
%F A169516 21*t^21 - 21*t^20 - 21*t^19 - 21*t^18 - 21*t^17 - 21*t^16 - 21*t^15 -
%F A169516 21*t^14 - 21*t^13 - 21*t^12 - 21*t^11 - 21*t^10 - 21*t^9 - 21*t^8 -
%F A169516 21*t^7 - 21*t^6 - 21*t^5 - 21*t^4 - 21*t^3 - 21*t^2 - 21*t + 1)
%K A169516 nonn
%O A169516 0,2
%A A169516 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009