cp's OEIS Frontend

A170131 Number of reduced words of length n in Coxeter group on 26 generators S_i with relations (S_i)^2 = (S_i S_j)^38 = I.

%I A170131 #6 May 14 2017 17:35:41
%S A170131 1,26,650,16250,406250,10156250,253906250,6347656250,158691406250,
%T A170131 3967285156250,99182128906250,2479553222656250,61988830566406250,
%U A170131 1549720764160156250,38743019104003906250,968575477600097656250
%N A170131 Number of reduced words of length n in Coxeter group on 26 generators S_i with relations (S_i)^2 = (S_i S_j)^38 = I.
%C A170131 The initial terms coincide with those of A170745, although the two sequences are eventually different.
%C A170131 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170131 <a href="/index/Rec#order_38">Index entries for linear recurrences with constant coefficients</a>, signature (24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, -300).
%F A170131 G.f. (t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 + 2*t^32 + 2*t^31 +
%F A170131 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 +
%F A170131 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 +
%F A170131 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 +
%F A170131 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(300*t^38 - 24*t^37 -
%F A170131 24*t^36 - 24*t^35 - 24*t^34 - 24*t^33 - 24*t^32 - 24*t^31 - 24*t^30 -
%F A170131 24*t^29 - 24*t^28 - 24*t^27 - 24*t^26 - 24*t^25 - 24*t^24 - 24*t^23 -
%F A170131 24*t^22 - 24*t^21 - 24*t^20 - 24*t^19 - 24*t^18 - 24*t^17 - 24*t^16 -
%F A170131 24*t^15 - 24*t^14 - 24*t^13 - 24*t^12 - 24*t^11 - 24*t^10 - 24*t^9 -
%F A170131 24*t^8 - 24*t^7 - 24*t^6 - 24*t^5 - 24*t^4 - 24*t^3 - 24*t^2 - 24*t + 1)
%K A170131 nonn
%O A170131 0,2
%A A170131 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009