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 A162809 #5 Nov 23 2016 15:26:32 %S A162809 1,23,506,10879,233772,5020785,107832648,2315920761,49739020254, %T A162809 1068244419627,22942674541710,492739584509403,10582562979139536, %U A162809 227281596017492709,4881324494907605052,104836155861245820165 %N A162809 Number of reduced words of length n in Coxeter group on 23 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I. %C A162809 The initial terms coincide with those of A170742, although the two sequences are eventually different. %C A162809 Computed with MAGMA using commands similar to those used to compute A154638. %H A162809 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (21, 21, -231). %F A162809 G.f.: (t^3 + 2*t^2 + 2*t + 1)/(231*t^3 - 21*t^2 - 21*t + 1) %K A162809 nonn %O A162809 0,2 %A A162809 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009