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 A167926 #18 Sep 11 2023 01:49:01
%S A167926 1,17,272,4352,69632,1114112,17825792,285212672,4563402752,
%T A167926 73014444032,1168231104512,18691697672192,299067162755072,
%U A167926 4785074604081152,76561193665298432,1224979098644774912,19599665578316398456
%N A167926 Number of reduced words of length n in Coxeter group on 17 generators S_i with relations (S_i)^2 = (S_i S_j)^16 = I.
%C A167926 The initial terms coincide with those of A170736, although the two sequences are eventually different.
%C A167926 Computed with MAGMA using commands similar to those used to compute A154638.
%H A167926 G. C. Greubel, <a href="/A167926/b167926.txt">Table of n, a(n) for n = 0..500</a>
%H A167926 <a href="/index/Rec#order_16">Index entries for linear recurrences with constant coefficients</a>, signature (15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,-120).
%F A167926 G.f.: (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)/( 120*t^16 - 15*t^15 - 15*t^14 - 15*t^13 - 15*t^12 - 15*t^11 - 15*t^10 - 15*t^9 - 15*t^8 - 15*t^7 - 15*t^6 - 15*t^5 - 15*t^4 - 15*t^3 - 15*t^2 - 15*t + 1).
%F A167926 From _G. C. Greubel_, Sep 10 2023: (Start)
%F A167926 G.f.: (1+t)*(1-t^16)/(1 - 16*t + 135*t^16 - 120*t^17).
%F A167926 a(n) = 15*Sum_{j=1..15} a(n-j) - 120*a(n-16). (End)
%t A167926 coxG[{16,120,-15}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Nov 27 2015 *)
%t A167926 CoefficientList[Series[(1+t)*(1-t^16)/(1-16*t+135*t^16-120*t^17), {t, 0, 50}], t] (* _G. C. Greubel_, Jul 01 2016; Sep 10 2023 *)
%o A167926 (Magma) R<x>:=PowerSeriesRing(Integers(), 40); Coefficients(R!( (1+x)*(1-x^16)/(1-16*x+135*x^16-120*x^17) )); // _G. C. Greubel_, Sep 10 2023
%o A167926 (SageMath)
%o A167926 def A167926_list(prec):
%o A167926 P.<x> = PowerSeriesRing(ZZ, prec)
%o A167926 return P( (1+x)*(1-x^16)/(1-16*x+135*x^16-120*x^17) ).list()
%o A167926 A167926_list(40) # _G. C. Greubel_, Sep 10 2023
%Y A167926 Cf. A154638, A169452, A170736.
%Y A167926 Cf. A167881, A167882, A167896 - A167900, A167908, A167914, A167916, A167919, A167922, A167923, A167924, A167927, A167929, A167931, A167933, A167935, A167937, A167938, A167940 - A167947, A167949 - A167962, A167978, A167980, A167988, A167989.
%K A167926 nonn
%O A167926 0,2
%A A167926 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009