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%I #8 May 03 2022 15:08:15
%S 1,13,156,1872,22464,269568,3234816,38817792,465813504,5589761970,
%T 67077142704,804925701294,9659108281680,115909297773984,
%U 1390911554013696,16690938416875008,200291258227027968
%N Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^9 = I.
%C The initial terms coincide with those of A170732, although the two sequences are eventually different.
%C Computed with MAGMA using commands similar to those used to compute A154638.
%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (11, 11, 11, 11, 11, 11, 11, 11, -66).
%F 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 1)/(66*t^9 - 11*t^8 - 11*t^7 - 11*t^6 - 11*t^5 - 11*t^4 - 11*t^3 -
%F 11*t^2 - 11*t + 1)
%t coxG[{9,66,-11}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, May 03 2022 *)
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009
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