cp's OEIS Frontend

A169473 Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.

%I A169473 #6 Nov 26 2016 07:23:21
%S A169473 1,28,756,20412,551124,14880348,401769396,10847773692,292889889684,
%T A169473 7908027021468,213516729579636,5764951698650172,155653695863554644,
%U A169473 4202649788315975388,113471544284531335476,3063731695682346057852
%N A169473 Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.
%C A169473 The initial terms coincide with those of A170747, although the two sequences are eventually different.
%C A169473 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169473 <a href="/index/Rec#order_33">Index entries for linear recurrences with constant coefficients</a>, signature (26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, -351).
%F A169473 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 A169473 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 A169473 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 A169473 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 A169473 1)/(351*t^33 - 26*t^32 - 26*t^31 - 26*t^30 - 26*t^29 - 26*t^28 - 26*t^27
%F A169473 - 26*t^26 - 26*t^25 - 26*t^24 - 26*t^23 - 26*t^22 - 26*t^21 - 26*t^20 -
%F A169473 26*t^19 - 26*t^18 - 26*t^17 - 26*t^16 - 26*t^15 - 26*t^14 - 26*t^13 -
%F A169473 26*t^12 - 26*t^11 - 26*t^10 - 26*t^9 - 26*t^8 - 26*t^7 - 26*t^6 - 26*t^5
%F A169473 - 26*t^4 - 26*t^3 - 26*t^2 - 26*t + 1)
%K A169473 nonn
%O A169473 0,2
%A A169473 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009