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 A167676 #9 Nov 24 2016 11:05:27
%S A167676 1,19,342,6156,110808,1994544,35901792,646232256,11632180608,
%T A167676 209379250944,3768826516992,67838877305856,1221099791505408,
%U A167676 21979796247097344,395636332447752192,7121453984059539285
%N A167676 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^15 = I.
%C A167676 The initial terms coincide with those of A170738, although the two sequences are eventually different.
%C A167676 Computed with MAGMA using commands similar to those used to compute A154638.
%H A167676 G. C. Greubel, <a href="/A167676/b167676.txt">Table of n, a(n) for n = 0..500</a>
%H A167676 <a href="/index/Rec#order_15">Index entries for linear recurrences with constant coefficients</a>, signature (17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, -153).
%F A167676 G.f.: (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)/(153*t^15 - 17*t^14 - 17*t^13 - 17*t^12 - 17*t^11 - 17*t^10 - 17*t^9 - 17*t^8 - 17*t^7 - 17*t^6 - 17*t^5 - 17*t^4 - 17*t^3 - 17*t^2 - 17*t + 1).
%t A167676 CoefficientList[Series[(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)/(153*t^15 - 17*t^14 - 17*t^13 - 17*t^12 - 17*t^11 - 17*t^10 - 17*t^9 - 17*t^8 - 17*t^7 - 17*t^6 - 17*t^5 - 17*t^4 - 17*t^3 - 17*t^2 - 17*t + 1), {t, 0, 50}], t] (* _G. C. Greubel_, Jun 19 2016 *)
%K A167676 nonn
%O A167676 0,2
%A A167676 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009