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%I #10 Feb 23 2024 04:20:41
%S 1,5,20,80,320,1280,5120,20480,81910,327600,1310250,5240400,20959200,
%T 83827200,335270400,1340928000,5363097690,21449933820,85789908630,
%U 343120332420,1372324139280,5488667867520,21952156999680,87798571269120
%N Number of reduced words of length n in Coxeter group on 5 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.
%C The initial terms coincide with those of A003947, 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_08">Index entries for linear recurrences with constant coefficients</a>, signature (3, 3, 3, 3, 3, 3, 3, -6).
%F G.f.: (t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(6*t^8 - 3*t^7 - 3*t^6 - 3*t^5 - 3*t^4 - 3*t^3 - 3*t^2 - 3*t + 1).
%K nonn
%O 0,2
%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009
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