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%I #5 Nov 23 2016 15:22:06
%S 1,12,132,1386,14520,151800,1586970,16589100,173411700,1812724650,
%T 18948963000,198079233000,2070582104250,21644420407500,
%U 226255667302500,2365118861366250,24723302164275000,258440148554775000
%N Number of reduced words of length n in Coxeter group on 12 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.
%C The initial terms coincide with those of A003954, 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 (10, 10, -55).
%F G.f.: (t^3 + 2*t^2 + 2*t + 1)/(55*t^3 - 10*t^2 - 10*t + 1)
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009