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Number of reduced words of length n in Coxeter group on 26 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.
0

%I #8 Nov 23 2016 18:30:33

%S 1,26,650,16250,406250,10156250,253906250,6347656250,158691405925,

%T 3967285140000,99182128297200,2479553202360000,61988829932250000,

%U 1549720745137500000,38743018549218750000,968575461750000000000

%N Number of reduced words of length n in Coxeter group on 26 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.

%C The initial terms coincide with those of A170745, 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 (24, 24, 24, 24, 24, 24, 24, -300).

%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)/(300*t^8 -

%F 24*t^7 - 24*t^6 - 24*t^5 - 24*t^4 - 24*t^3 - 24*t^2 - 24*t + 1)

%t coxG[{8,300,-24}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jul 19 2015 *)

%K nonn

%O 0,2

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