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 A165365 #8 Dec 25 2024 19:32:59
%S A165365 1,23,506,11132,244904,5387888,118533536,2607737792,57370231424,
%T A165365 1262145091075,27767191998084,610878223835649,13439320921695900,
%U A165365 295665060218165484,6504631323498465696,143101889088340396368
%N A165365 Number of reduced words of length n in Coxeter group on 23 generators S_i with relations (S_i)^2 = (S_i S_j)^9 = I.
%C A165365 The initial terms coincide with those of A170742, although the two sequences are eventually different.
%C A165365 Computed with MAGMA using commands similar to those used to compute A154638.
%H A165365 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (21, 21, 21, 21, 21, 21, 21, 21, -231).
%F A165365 G.f. (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 +
%F A165365 1)/(231*t^9 - 21*t^8 - 21*t^7 - 21*t^6 - 21*t^5 - 21*t^4 - 21*t^3 -
%F A165365 21*t^2 - 21*t + 1)
%t A165365 coxG[{9,231,-21}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Dec 25 2024 *)
%K A165365 nonn
%O A165365 0,2
%A A165365 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009