cp's OEIS Frontend

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.

A167672 Number of reduced words of length n in Coxeter group on 16 generators S_i with relations (S_i)^2 = (S_i S_j)^15 = I.

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%I A167672 #11 Nov 24 2016 11:04:31
%S A167672 1,16,240,3600,54000,810000,12150000,182250000,2733750000,41006250000,
%T A167672 615093750000,9226406250000,138396093750000,2075941406250000,
%U A167672 31139121093750000,467086816406249880,7006302246093746400
%N A167672 Number of reduced words of length n in Coxeter group on 16 generators S_i with relations (S_i)^2 = (S_i S_j)^15 = I.
%C A167672 The initial terms coincide with those of A170735, although the two sequences are eventually different.
%C A167672 Computed with MAGMA using commands similar to those used to compute A154638.
%H A167672 G. C. Greubel, <a href="/A167672/b167672.txt">Table of n, a(n) for n = 0..500</a>
%H A167672 <a href="/index/Rec#order_15">Index entries for linear recurrences with constant coefficients</a>, signature (14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, -105).
%F A167672 G.f.: (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)/(105*t^15 - 14*t^14 - 14*t^13 - 14*t^12 - 14*t^11 - 14*t^10 - 14*t^9 - 14*t^8 - 14*t^7 - 14*t^6 - 14*t^5 - 14*t^4 - 14*t^3 - 14*t^2 - 14*t + 1).
%t A167672 CoefficientList[Series[(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)/(105*t^15 - 14*t^14 - 14*t^13 - 14*t^12 - 14*t^11 - 14*t^10 - 14*t^9 - 14*t^8 - 14*t^7 - 14*t^6 - 14*t^5 - 14*t^4 - 14*t^3 - 14*t^2 - 14*t + 1), {t, 0, 50}], t] (* _G. C. Greubel_, Jun 19 2016 *)
%t A167672 coxG[{15,105,-14}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jul 27 2016 *)
%K A167672 nonn
%O A167672 0,2
%A A167672 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009