cp's OEIS Frontend

A170184 Number of reduced words of length n in Coxeter group on 31 generators S_i with relations (S_i)^2 = (S_i S_j)^39 = I.

%I A170184 #8 Nov 22 2016 15:56:31
%S A170184 1,31,930,27900,837000,25110000,753300000,22599000000,677970000000,
%T A170184 20339100000000,610173000000000,18305190000000000,549155700000000000,
%U A170184 16474671000000000000,494240130000000000000,14827203900000000000000
%N A170184 Number of reduced words of length n in Coxeter group on 31 generators S_i with relations (S_i)^2 = (S_i S_j)^39 = I.
%C A170184 The initial terms coincide with those of A170750, although the two sequences are eventually different.
%C A170184 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170184 <a href="/index/Rec#order_39">Index entries for linear recurrences with constant coefficients</a>, signature (29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, -435).
%F A170184 G.f. (t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 + 2*t^32 +
%F A170184 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 + 2*t^25 + 2*t^24 +
%F A170184 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 +
%F A170184 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 + 2*t^8 +
%F A170184 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(435*t^39 -
%F A170184 29*t^38 - 29*t^37 - 29*t^36 - 29*t^35 - 29*t^34 - 29*t^33 - 29*t^32 -
%F A170184 29*t^31 - 29*t^30 - 29*t^29 - 29*t^28 - 29*t^27 - 29*t^26 - 29*t^25 -
%F A170184 29*t^24 - 29*t^23 - 29*t^22 - 29*t^21 - 29*t^20 - 29*t^19 - 29*t^18 -
%F A170184 29*t^17 - 29*t^16 - 29*t^15 - 29*t^14 - 29*t^13 - 29*t^12 - 29*t^11 -
%F A170184 29*t^10 - 29*t^9 - 29*t^8 - 29*t^7 - 29*t^6 - 29*t^5 - 29*t^4 - 29*t^3 -
%F A170184 29*t^2 - 29*t + 1)
%t A170184 coxG[{39,435,-29}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Aug 13 2015 *)
%K A170184 nonn
%O A170184 0,2
%A A170184 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009