cp's OEIS Frontend

A170118 Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^38 = I.

%I A170118 #6 May 14 2017 17:31:57
%S A170118 1,13,156,1872,22464,269568,3234816,38817792,465813504,5589762048,
%T A170118 67077144576,804925734912,9659108818944,115909305827328,
%U A170118 1390911669927936,16690940039135232,200291280469622784
%N A170118 Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^38 = I.
%C A170118 The initial terms coincide with those of A170732, although the two sequences are eventually different.
%C A170118 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170118 <a href="/index/Rec#order_38">Index entries for linear recurrences with constant coefficients</a>, signature (11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, -66).
%F A170118 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 A170118 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 A170118 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 A170118 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 A170118 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(66*t^38 - 11*t^37 -
%F A170118 11*t^36 - 11*t^35 - 11*t^34 - 11*t^33 - 11*t^32 - 11*t^31 - 11*t^30 -
%F A170118 11*t^29 - 11*t^28 - 11*t^27 - 11*t^26 - 11*t^25 - 11*t^24 - 11*t^23 -
%F A170118 11*t^22 - 11*t^21 - 11*t^20 - 11*t^19 - 11*t^18 - 11*t^17 - 11*t^16 -
%F A170118 11*t^15 - 11*t^14 - 11*t^13 - 11*t^12 - 11*t^11 - 11*t^10 - 11*t^9 -
%F A170118 11*t^8 - 11*t^7 - 11*t^6 - 11*t^5 - 11*t^4 - 11*t^3 - 11*t^2 - 11*t + 1)
%K A170118 nonn
%O A170118 0,2
%A A170118 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009