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 A165693 #8 Nov 05 2017 09:37:54
%S A165693 1,42,1722,70602,2894682,118681962,4865960442,199504378122,
%T A165693 8179679503002,335366859622221,13750041244475760,563751691022059680,
%U A165693 23113819331845141200,947666592603219256320,38854330296632296661040
%N A165693 Number of reduced words of length n in Coxeter group on 42 generators S_i with relations (S_i)^2 = (S_i S_j)^9 = I.
%C A165693 The initial terms coincide with those of A170761, although the two sequences are eventually different.
%C A165693 Computed with MAGMA using commands similar to those used to compute A154638.
%H A165693 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (40, 40, 40, 40, 40, 40, 40, 40, -820).
%F A165693 G.f. (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 +
%F A165693 1)/(820*t^9 - 40*t^8 - 40*t^7 - 40*t^6 - 40*t^5 - 40*t^4 - 40*t^3 -
%F A165693 40*t^2 - 40*t + 1)
%t A165693 coxG[{9,820,-40}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Nov 05 2017 *)
%K A165693 nonn
%O A165693 0,2
%A A165693 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009