cp's OEIS Frontend

A170138 Number of reduced words of length n in Coxeter group on 33 generators S_i with relations (S_i)^2 = (S_i S_j)^38 = I.

%I A170138 #6 May 14 2017 17:37:36
%S A170138 1,33,1056,33792,1081344,34603008,1107296256,35433480192,
%T A170138 1133871366144,36283883716608,1161084278931456,37154696925806592,
%U A170138 1188950301625810944,38046409652025950208,1217485108864830406656,38959523483674573012992
%N A170138 Number of reduced words of length n in Coxeter group on 33 generators S_i with relations (S_i)^2 = (S_i S_j)^38 = I.
%C A170138 The initial terms coincide with those of A170752, although the two sequences are eventually different.
%C A170138 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170138 <a href="/index/Rec#order_38">Index entries for linear recurrences with constant coefficients</a>, signature (31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, -496).
%F A170138 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 A170138 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 A170138 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 A170138 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 A170138 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(496*t^38 - 31*t^37 -
%F A170138 31*t^36 - 31*t^35 - 31*t^34 - 31*t^33 - 31*t^32 - 31*t^31 - 31*t^30 -
%F A170138 31*t^29 - 31*t^28 - 31*t^27 - 31*t^26 - 31*t^25 - 31*t^24 - 31*t^23 -
%F A170138 31*t^22 - 31*t^21 - 31*t^20 - 31*t^19 - 31*t^18 - 31*t^17 - 31*t^16 -
%F A170138 31*t^15 - 31*t^14 - 31*t^13 - 31*t^12 - 31*t^11 - 31*t^10 - 31*t^9 -
%F A170138 31*t^8 - 31*t^7 - 31*t^6 - 31*t^5 - 31*t^4 - 31*t^3 - 31*t^2 - 31*t + 1)
%K A170138 nonn
%O A170138 0,2
%A A170138 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009