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 A164815 #13 Feb 22 2024 13:34:03
%S A164815 1,13,156,1872,22464,269568,3234816,38817792,465813426,5589760176,
%T A164815 67077110958,804925197648,9659100765600,115909189913088,
%U A164815 1390910047667712,16690917796540416,200290980252825462
%N A164815 Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.
%C A164815 The initial terms coincide with those of A170732, although the two sequences are eventually different.
%C A164815 Computed with MAGMA using commands similar to those used to compute A154638.
%H A164815 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (11,11,11,11,11,11,11,-66).
%F A164815 G.f.: (t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(66*t^8 - 11*t^7 - 11*t^6 - 11*t^5 - 11*t^4 - 11*t^3 - 11*t^2 - 11*t + 1)
%t A164815 With[{num=Total[2t^Range[7]]+t^8+1,den=Total[-11 t^Range[7]]+66t^8+1}, CoefficientList[Series[num/den,{t,0,30}],t]] (* _Harvey P. Dale_, Aug 21 2011 *)
%K A164815 nonn
%O A164815 0,2
%A A164815 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009