cp's OEIS Frontend

A169511 Number of reduced words of length n in Coxeter group on 18 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.

%I A169511 #6 Nov 26 2016 07:34:38
%S A169511 1,18,306,5202,88434,1503378,25557426,434476242,7386096114,
%T A169511 125563633938,2134581776946,36287890208082,616894133537394,
%U A169511 10487200270135698,178282404592306866,3030800878069216722,51523614927176684274
%N A169511 Number of reduced words of length n in Coxeter group on 18 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.
%C A169511 The initial terms coincide with those of A170737, although the two sequences are eventually different.
%C A169511 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169511 <a href="/index/Rec#order_34">Index entries for linear recurrences with constant coefficients</a>, signature (16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, -136).
%F A169511 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 A169511 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 A169511 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 A169511 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 A169511 2*t + 1)/(136*t^34 - 16*t^33 - 16*t^32 - 16*t^31 - 16*t^30 - 16*t^29 -
%F A169511 16*t^28 - 16*t^27 - 16*t^26 - 16*t^25 - 16*t^24 - 16*t^23 - 16*t^22 -
%F A169511 16*t^21 - 16*t^20 - 16*t^19 - 16*t^18 - 16*t^17 - 16*t^16 - 16*t^15 -
%F A169511 16*t^14 - 16*t^13 - 16*t^12 - 16*t^11 - 16*t^10 - 16*t^9 - 16*t^8 -
%F A169511 16*t^7 - 16*t^6 - 16*t^5 - 16*t^4 - 16*t^3 - 16*t^2 - 16*t + 1)
%K A169511 nonn
%O A169511 0,2
%A A169511 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009