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 A162960 #5 Nov 23 2016 15:38:02 %S A162960 1,9,72,576,4572,36288,288036,2286144,18145260,144020016,1143094932, %T A162960 9072809424,72011403324,571558593312,4536492984324,36006402202848, %U A162960 285784857170316,2268290625889680,18003551393278836,142895208872692080 %N A162960 Number of reduced words of length n in Coxeter group on 9 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I. %C A162960 The initial terms coincide with those of A003951, although the two sequences are eventually different. %C A162960 Computed with MAGMA using commands similar to those used to compute A154638. %H A162960 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (7, 7, 7, -28). %F A162960 G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(28*t^4 - 7*t^3 - 7*t^2 - 7*t + 1) %K A162960 nonn %O A162960 0,2 %A A162960 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009