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 A166693 #12 Nov 24 2016 09:45:19
%S A166693 1,40,1560,60840,2372760,92537640,3608967960,140749750440,
%T A166693 5489240267160,214080370419240,8349134446350360,325616243407664040,
%U A166693 12699033492898896780,495262306223056944000,19315229942699219630400
%N A166693 Number of reduced words of length n in Coxeter group on 40 generators S_i with relations (S_i)^2 = (S_i S_j)^12 = I.
%C A166693 The initial terms coincide with those of A170759, although the two sequences are eventually different.
%C A166693 Computed with MAGMA using commands similar to those used to compute A154638.
%H A166693 G. C. Greubel, <a href="/A166693/b166693.txt">Table of n, a(n) for n = 0..500</a>
%H A166693 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, -741).
%F A166693 G.f.: (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)/(741*t^12 - 38*t^11 - 38*t^10 - 38*t^9 -38*t^8 -38*t^7 -38*t^6 - 38*t^5 - 38*t^4 - 38*t^3 - 38*t^2 - 38*t + 1).
%t A166693 CoefficientList[Series[(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)/(741*t^12 - 38*t^11 - 38*t^10 - 38*t^9 - 38*t^8 - 38*t^7 - 38*t^6 - 38*t^5 - 38*t^4 - 38*t^3 - 38*t^2 - 38*t + 1), {t, 0, 50}], t] (* _G. C. Greubel_, May 23 2016 *)
%t A166693 coxG[{12,741,-38}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Sep 20 2016 *)
%K A166693 nonn
%O A166693 0,2
%A A166693 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009