cp's OEIS Frontend

A169395 Number of reduced words of length n in Coxeter group on 46 generators S_i with relations (S_i)^2 = (S_i S_j)^31 = I.

%I A169395 #13 Oct 12 2024 01:40:42
%S A169395 1,46,2070,93150,4191750,188628750,8488293750,381973218750,
%T A169395 17188794843750,773495767968750,34807309558593750,1566328930136718750,
%U A169395 70484801856152343750,3171816083526855468750,142731723758708496093750
%N A169395 Number of reduced words of length n in Coxeter group on 46 generators S_i with relations (S_i)^2 = (S_i S_j)^31 = I.
%C A169395 The initial terms coincide with those of A170765, although the two sequences are eventually different.
%C A169395 First disagreement at index 31: a(31) = 1816072762627103702777571908427402377128601074217715, A170765(31) = 1816072762627103702777571908427402377128601074218750. - _Klaus Brockhaus_, Jun 17 2011
%C A169395 Computed with Magma using commands similar to those used to compute A154638.
%H A169395 <a href="/index/Rec#order_31">Index entries for linear recurrences with constant coefficients</a>, signature (44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, -990).
%F A169395 G.f.: (t^31 + 2*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)/(990*t^31 - 44*t^30 - 44*t^29 - 44*t^28 - 44*t^27 - 44*t^26 - 44*t^25 - 44*t^24 - 44*t^23 - 44*t^22 - 44*t^21 - 44*t^20 - 44*t^19 - 44*t^18 - 44*t^17 - 44*t^16 - 44*t^15 - 44*t^14 - 44*t^13 - 44*t^12 - 44*t^11 - 44*t^10 - 44*t^9 - 44*t^8 - 44*t^7 - 44*t^6 - 44*t^5 - 44*t^4 - 44*t^3 - 44*t^2 - 44*t + 1).
%Y A169395 Cf. A170765 (G.f.: (1+x)/(1-45*x)).
%K A169395 nonn
%O A169395 0,2
%A A169395 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009