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%I #5 Nov 23 2016 15:37:09
%S 1,6,30,150,735,3600,17640,86400,423210,2073000,10154040,49737000,
%T 243624060,1193330400,5845225440,28631349600,140243381160,
%U 686946520800,3364832751840,16481777119200,80731791755760,395444141299200
%N Number of reduced words of length n in Coxeter group on 6 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.
%C The initial terms coincide with those of A003948, 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 (4, 4, 4, -10).
%F G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(10*t^4 - 4*t^3 - 4*t^2 - 4*t + 1)
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009
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