cp's OEIS Frontend

A169502 Number of reduced words of length n in Coxeter group on 9 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.

%I A169502 #8 Apr 07 2018 17:27:41
%S A169502 1,9,72,576,4608,36864,294912,2359296,18874368,150994944,1207959552,
%T A169502 9663676416,77309411328,618475290624,4947802324992,39582418599936,
%U A169502 316659348799488,2533274790395904,20266198323167232,162129586585337856
%N A169502 Number of reduced words of length n in Coxeter group on 9 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.
%C A169502 The initial terms coincide with those of A003951, although the two sequences are eventually different.
%C A169502 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169502 <a href="/index/Rec#order_34">Index entries for linear recurrences with constant coefficients</a>, signature (7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, -28).
%F A169502 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 A169502 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 A169502 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 A169502 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 A169502 2*t + 1)/(28*t^34 - 7*t^33 - 7*t^32 - 7*t^31 - 7*t^30 - 7*t^29 - 7*t^28
%F A169502 - 7*t^27 - 7*t^26 - 7*t^25 - 7*t^24 - 7*t^23 - 7*t^22 - 7*t^21 - 7*t^20
%F A169502 - 7*t^19 - 7*t^18 - 7*t^17 - 7*t^16 - 7*t^15 - 7*t^14 - 7*t^13 - 7*t^12
%F A169502 - 7*t^11 - 7*t^10 - 7*t^9 - 7*t^8 - 7*t^7 - 7*t^6 - 7*t^5 - 7*t^4 -
%F A169502 7*t^3 - 7*t^2 - 7*t + 1)
%t A169502 coxG[{34,28,-7}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Apr 07 2018 *)
%K A169502 nonn
%O A169502 0,2
%A A169502 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009