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 A162806 #7 Jul 10 2020 15:20:18
%S A162806 1,20,380,7030,129960,2400840,44352270,819332820,15135787980,
%T A162806 279607936230,5165281123560,95419783331640,1762718203098270,
%U A162806 32563220683609620,601550117011031580,11112615265773737430
%N A162806 Number of reduced words of length n in Coxeter group on 20 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.
%C A162806 The initial terms coincide with those of A170739, although the two sequences are eventually different.
%C A162806 Computed with MAGMA using commands similar to those used to compute A154638.
%H A162806 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (18, 18, -171).
%F A162806 G.f.: (t^3 + 2*t^2 + 2*t + 1)/(171*t^3 - 18*t^2 - 18*t + 1)
%t A162806 coxG[{3,171,-18}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jul 10 2020 *)
%K A162806 nonn
%O A162806 0,2
%A A162806 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009