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 A168859 #11 Nov 24 2016 18:39:30
%S A168859 1,38,1406,52022,1924814,71218118,2635070366,97497603542,
%T A168859 3607411331054,133474219248998,4938546112212926,182726206151878262,
%U A168859 6760869627619495694,250152176221921340678,9255630520211089605086
%N A168859 Number of reduced words of length n in Coxeter group on 38 generators S_i with relations (S_i)^2 = (S_i S_j)^20 = I.
%C A168859 The initial terms coincide with those of A170757, although the two sequences are eventually different.
%C A168859 First disagreement at index 20: a(20) = 23747415657652000854434530915471, A170757(20) = 23747415657652000854434530916174. - Klaus Brockhaus, Apr 04 2011
%C A168859 Computed with MAGMA using commands similar to those used to compute A154638.
%H A168859 <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, -666).
%F A168859 G.f.: (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)/(666*t^20 - 36*t^19 - 36*t^18 - 36*t^17 - 36*t^16 - 36*t^15 - 36*t^14 - 36*t^13 - 36*t^12 - 36*t^11 - 36*t^10 - 36*t^9 - 36*t^8 - 36*t^7 - 36*t^6 - 36*t^5 - 36*t^4 - 36*t^3 - 36*t^2 - 36*t + 1).
%t A168859 With[{num=Total[2t^Range[19]]+t^20+1,den=Total[-36 t^Range[19]]+ 666t^20+1}, CoefficientList[Series[num/den,{t,0,30}],t]] (* _Harvey P. Dale_, Mar 31 2012 *)
%Y A168859 Cf. A170757 (G.f.: (1+x)/(1-37*x)).
%K A168859 nonn
%O A168859 0,2
%A A168859 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009