cp's OEIS Frontend

A169338 Number of reduced words of length n in Coxeter group on 37 generators S_i with relations (S_i)^2 = (S_i S_j)^30 = I.

%I A169338 #10 May 10 2018 00:27:54
%S A169338 1,37,1332,47952,1726272,62145792,2237248512,80540946432,
%T A169338 2899474071552,104381066575872,3757718396731392,135277862282330112,
%U A169338 4870003042163884032,175320109517899825152,6311523942644393705472
%N A169338 Number of reduced words of length n in Coxeter group on 37 generators S_i with relations (S_i)^2 = (S_i S_j)^30 = I.
%C A169338 The initial terms coincide with those of A170756, although the two sequences are eventually different.
%C A169338 First disagreement at index 30: a(30) = 50231280146819514641803939836935009528595873126, A170756(30) = 50231280146819514641803939836935009528595873792. - _Klaus Brockhaus_, Jun 23 2011
%C A169338 Computed with Magma using commands similar to those used to compute A154638.
%H A169338 <a href="/index/Rec#order_30">Index entries for linear recurrences with constant coefficients</a>, signature (35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, 35, -630).
%F A169338 G.f.: (t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 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 + 2*t + 1)/(630*t^30 - 35*t^29 - 35*t^28 - 35*t^27 - 35*t^26 - 35*t^25 - 35*t^24 - 35*t^23 - 35*t^22 - 35*t^21 - 35*t^20 - 35*t^19 - 35*t^18 - 35*t^17 - 35*t^16 - 35*t^15 - 35*t^14 - 35*t^13 - 35*t^12 - 35*t^11 - 35*t^10 - 35*t^9 - 35*t^8 - 35*t^7 - 35*t^6 - 35*t^5 - 35*t^4 - 35*t^3 - 35*t^2 - 35*t + 1).
%Y A169338 Cf. A170756 (G.f.: (1+x)/(1-36*x)).
%K A169338 nonn
%O A169338 0,2
%A A169338 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009