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 A168857 #8 Nov 24 2016 18:38:58 %S A168857 1,36,1260,44100,1543500,54022500,1890787500,66177562500, %T A168857 2316214687500,81067514062500,2837362992187500,99307704726562500, %U A168857 3475769665429687500,121651938290039062500,4257817840151367187500,149023624405297851562500 %N A168857 Number of reduced words of length n in Coxeter group on 36 generators S_i with relations (S_i)^2 = (S_i S_j)^20 = I. %C A168857 The initial terms coincide with those of A170755, although the two sequences are eventually different. %C A168857 First disagreement at index 20: a(20) = 7827000173062003097534179686870, A170755(20) = 7827000173062003097534179687500. - Klaus Brockhaus, Apr 04 2011 %C A168857 Computed with MAGMA using commands similar to those used to compute A154638. %H A168857 <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, -595). %F A168857 G.f.: (t^20 + 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 + 2*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)/(595*t^20 - 34*t^19 - 34*t^18 - 34*t^17 - 34*t^16 - 34*t^15 - 34*t^14 - 34*t^13 - 34*t^12 - 34*t^11 - 34*t^10 - 34*t^9 - 34*t^8 - 34*t^7 - 34*t^6 - 34*t^5 - 34*t^4 - 34*t^3 - 34*t^2 - 34*t + 1). %Y A168857 Cf. A170755 (G.f.: (1+x)/(1-35*x)). %K A168857 nonn %O A168857 0,2 %A A168857 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009