This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A167989 #21 Jan 15 2023 02:29:05
%S A167989 1,50,2450,120050,5882450,288240050,14123762450,692064360050,
%T A167989 33911153642450,1661646528480050,81420679895522450,
%U A167989 3989613314880600050,195491052429149402450,9579061569028320720050,469374016882387715282450
%N A167989 Number of reduced words of length n in Coxeter group on 50 generators S_i with relations (S_i)^2 = (S_i S_j)^16 = I.
%C A167989 The initial terms coincide with those of A170769, although the two sequences are eventually different.
%C A167989 Computed with MAGMA using commands similar to those used to compute A154638.
%H A167989 G. C. Greubel, <a href="/A167989/b167989.txt">Table of n, a(n) for n = 0..500</a>
%H A167989 <a href="/index/Rec#order_16">Index entries for linear recurrences with constant coefficients</a>, signature (48,48,48,48,48,48,48,48,48,48,48,48,48,48,48,-1176).
%F A167989 G.f.: (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)/( 1176*t^16 - 48*t^15 - 48*t^14 - 48*t^13 - 48*t^12 - 48*t^11 - 48*t^10 - 48*t^9 - 48*t^8 - 48*t^7 - 48*t^6 - 48*t^5 - 48*t^4 - 48*t^3 - 48*t^2 - 48*t + 1).
%F A167989 From _G. C. Greubel_, Jan 14 2023: (Start)
%F A167989 a(n) = -1176*a(n-16) + 48*Sum_{j=1..15} a(n-j).
%F A167989 G.f.: (1+x)*(1-x^16)/(1-49*x+1224*x^16-1176*x^17). (End)
%t A167989 CoefficientList[Series[(1+x)*(1-x^16)/(1-49*x+1224*x^16-1176*x^17), {x, 0, 50}], x] (* _G. C. Greubel_, Jul 03 2016; Jan 14 2023 *)
%t A167989 coxG[{16, 1176, -48, 10}] (* The coxG program is at A169452 *) (* _G. C. Greubel_, Jan 14 2023 *)
%o A167989 (Magma) R<x>:=PowerSeriesRing(Integers(), 40); Coefficients(R!( (1+x)*(1-x^16)/(1-49*x+1224*x^16-1176*x^17) )); // _G. C. Greubel_, Jan 14 2023
%o A167989 (SageMath)
%o A167989 def A167989_list(prec):
%o A167989 P.<x> = PowerSeriesRing(ZZ, prec)
%o A167989 return P( (1+x)*(1-x^16)/(1-49*x+1224*x^16-1176*x^17) ).list()
%o A167989 A167989_list(40) # _G. C. Greubel_, Jan 14 2023
%Y A167989 Cf. A154638, A169452, A170769.
%K A167989 nonn
%O A167989 0,2
%A A167989 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009