A164867 - OEIS

%I #8 Nov 23 2016 18:27:01

%S 1,16,240,3600,54000,810000,12150000,182250000,2733749880,41006246400,

%T 615093669120,9226404633600,138396063456000,2075940861120000,

%U 31139111556000000,467086652928000000,7006299487740014280

%N Number of reduced words of length n in Coxeter group on 16 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.

%C The initial terms coincide with those of A170735, 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 (14, 14, 14, 14, 14, 14, 14, -105).

%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)/(105*t^8 -

%F 14*t^7 - 14*t^6 - 14*t^5 - 14*t^4 - 14*t^3 - 14*t^2 - 14*t + 1)

%t coxG[{8,105,-14}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Mar 16 2015 *)

%K nonn

%O 0,2

%A _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009