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 A168976 #8 Nov 25 2016 10:21:40 %S A168976 1,11,110,1100,11000,110000,1100000,11000000,110000000,1100000000, %T A168976 11000000000,110000000000,1100000000000,11000000000000, %U A168976 110000000000000,1100000000000000,11000000000000000,110000000000000000 %N A168976 Number of reduced words of length n in Coxeter group on 11 generators S_i with relations (S_i)^2 = (S_i S_j)^23 = I. %C A168976 The initial terms coincide with those of A003953, although the two sequences are eventually different. %C A168976 First disagreement at index 23: a(23) = 109999999999999999999945, A003953(23) = 110000000000000000000000. - Klaus Brockhaus, Apr 19 2011 %C A168976 Computed with MAGMA using commands similar to those used to compute A154638. %H A168976 <a href="/index/Rec#order_23">Index entries for linear recurrences with constant coefficients</a>, signature (9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, -45). %F A168976 G.f.: (t^23 + 2*t^22 + 2*t^21 + 2*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)/(45*t^23 - 9*t^22 - 9*t^21 - 9*t^20 - 9*t^19 - 9*t^18 - 9*t^17 - 9*t^16 - 9*t^15 - 9*t^14 - 9*t^13 - 9*t^12 - 9*t^11 - 9*t^10 - 9*t^9 - 9*t^8 - 9*t^7 - 9*t^6 - 9*t^5 - 9*t^4 - 9*t^3 - 9*t^2 - 9*t + 1). %Y A168976 Cf. A003953 (G.f.: (1+x)/(1-10*x)). %K A168976 nonn %O A168976 0,2 %A A168976 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009