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%I #5 Nov 23 2016 15:28:12
%S 1,28,756,20034,530712,14054040,372171618,9855587196,260988761124,
%T 6911320818402,183020737961880,4846626473132808,128344953881202786,
%U 3398740810188105564,90003063973732401492,2383397845569631005570
%N Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.
%C The initial terms coincide with those of A170747, 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_03">Index entries for linear recurrences with constant coefficients</a>, signature (26, 26, -351).
%F G.f.: (t^3 + 2*t^2 + 2*t + 1)/(351*t^3 - 26*t^2 - 26*t + 1)
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009
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