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 A165185 #6 Nov 23 2016 22:05:18 %S A165185 1,5,20,80,320,1280,5120,20480,81920,327670,1310640,5242410,20969040, %T A165185 83873760,335485440,1341903360,5367459840,21469224960,85874442330, %U A165185 343487939580,1373912440470,5495492494980,21981340930320,87922847594880 %N A165185 Number of reduced words of length n in Coxeter group on 5 generators S_i with relations (S_i)^2 = (S_i S_j)^9 = I. %C A165185 The initial terms coincide with those of A003947, although the two sequences are eventually different. %C A165185 Computed with MAGMA using commands similar to those used to compute A154638. %H A165185 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (3, 3, 3, 3, 3, 3, 3, 3, -6). %F A165185 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 A165185 1)/(6*t^9 - 3*t^8 - 3*t^7 - 3*t^6 - 3*t^5 - 3*t^4 - 3*t^3 - 3*t^2 - 3*t %F A165185 + 1) %K A165185 nonn %O A165185 0,2 %A A165185 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009