%I
%S 1,15,210,2940,41055,573300,8005725,111793500,1561106820,21799608285,
%T 304414090890,4250899269435,59360407871310,828920611657320,
%U 11575213262103855,161638593827703720,2257153663002754425
%N Number of reduced words of length n in Coxeter group on 15 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.
%C The initial terms coincide with those of A170734, 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_04">Index entries for linear recurrences with constant coefficients</a>, signature (13, 13, 13, 91).
%F G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(91*t^4  13*t^3  13*t^2  13*t + 1)
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009
