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 A163290 #11 Mar 22 2020 12:30:54
%S A163290 1,50,2450,120050,5881225,288120000,14114940000,691488000000,
%T A163290 33875854559400,1659571130851200,81302047554268800,
%U A163290 3982970548016611200,195124905996721243200,9559128916780140902400,468299754871670360217600
%N A163290 Number of reduced words of length n in Coxeter group on 50 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.
%C A163290 The initial terms coincide with those of A170769, although the two sequences are eventually different.
%C A163290 Computed with MAGMA using commands similar to those used to compute A154638.
%H A163290 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (48, 48, 48, -1176).
%F A163290 G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(1176*t^4 - 48*t^3 - 48*t^2 - 48*t + 1).
%t A163290 CoefficientList[Series[(t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(1176*t^4 - 48*t^3 - 48*t^2 - 48*t + 1), {t,0,50}], t] (* or *) Join[{1}, LinearRecurrence[ {48,48,48,-1176}, {50, 2450, 120050, 5881225}, 25]] (* _G. C. Greubel_, Dec 17 2016 *)
%t A163290 coxG[{4,1176,-48}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Mar 22 2020 *)
%o A163290 (PARI) Vec((t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(1176*t^4 - 48*t^3 - 48*t^2 - 48*t + 1) + O(t^50)) \\ _G. C. Greubel_, Dec 17 2016
%K A163290 nonn
%O A163290 0,2
%A A163290 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009