%I #8 Oct 09 2018 12:32:05
%S 1,38,1406,52022,1924814,71218118,2635070366,97497603542,
%T 3607411331054,133474219248295,4938546112160904,182726206148991744,
%U 6760869627477111480,250152176215336551984,9255630519918739230696
%N Number of reduced words of length n in Coxeter group on 38 generators S_i with relations (S_i)^2 = (S_i S_j)^9 = I.
%C The initial terms coincide with those of A170757, 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 (36, 36, 36, 36, 36, 36, 36, 36, -666).
%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)/(666*t^9 - 36*t^8 - 36*t^7 - 36*t^6 - 36*t^5 - 36*t^4 - 36*t^3 -
%F 36*t^2 - 36*t + 1)
%t coxG[{9,666,-36}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Oct 09 2018 *)
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009