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 A166855 #9 Nov 24 2016 09:47:59
%S A166855 1,49,2352,112896,5419008,260112384,12485394432,599298932736,
%T A166855 28766348771328,1380784741023744,66277667569139712,
%U A166855 3181328043318706176,152703746079297895272,7329779811806298916608,351829430966702345288856
%N A166855 Number of reduced words of length n in Coxeter group on 49 generators S_i with relations (S_i)^2 = (S_i S_j)^12 = I.
%C A166855 The initial terms coincide with those of A170768, although the two sequences are eventually different.
%C A166855 Computed with MAGMA using commands similar to those used to compute A154638.
%H A166855 G. C. Greubel, <a href="/A166855/b166855.txt">Table of n, a(n) for n = 0..500</a>
%H A166855 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, -1128).
%F A166855 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)/(1128*t^12 - 47*t^11 - 47*t^10 - 47*t^9 -47*t^8 -47*t^7 -47*t^6 - 47*t^5 - 47*t^4 - 47*t^3 - 47*t^2 - 47*t + 1).
%t A166855 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)/(1128*t^12 - 47*t^11 - 47*t^10 - 47*t^9 - 47*t^8 - 47*t^7 - 47*t^6 - 47*t^5 - 47*t^4 - 47*t^3 - 47*t^2 - 47*t + 1), {t, 0, 50}], t] (* _G. C. Greubel_, May 25 2016 *)
%K A166855 nonn
%O A166855 0,2
%A A166855 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009