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 A166612 #11 Jun 03 2019 19:51:38
%S A166612 1,25,600,14400,345600,8294400,199065600,4777574400,114661785600,
%T A166612 2751882854400,66045188505600,1585084524134400,38042028579225300,
%U A166612 913008685901400000,21912208461633427500,525893003079198120000
%N A166612 Number of reduced words of length n in Coxeter group on 25 generators S_i with relations (S_i)^2 = (S_i S_j)^12 = I.
%C A166612 The initial terms coincide with those of A170744, although the two sequences are eventually different.
%C A166612 Computed with MAGMA using commands similar to those used to compute A154638.
%H A166612 G. C. Greubel, <a href="/A166612/b166612.txt">Table of n, a(n) for n = 0..500</a>
%H A166612 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, -276).
%F A166612 G.f.: (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)/(276*t^12 - 23*t^11 - 23*t^10 - 23*t^9 -23*t^8 -23*t^7 - 23*t^6 - 23*t^5 - 23*t^4 - 23*t^3 - 23*t^2 -23*t + 1).
%t A166612 CoefficientList[Series[(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)/(276*t^12 - 23*t^11 - 23*t^10 - 23*t^9 - 23*t^8 - 23*t^7 - 23*t^6 - 23*t^5 - 23*t^4 - 23*t^3 - 23*t^2 - 23*t + 1), {t, 0, 50}], t] (* _G. C. Greubel_, May 18 2016 *)
%t A166612 coxG[{12,276,-23}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jun 03 2019 *)
%K A166612 nonn
%O A166612 0,2
%A A166612 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009