cp's OEIS Frontend

A169512 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.

%I A169512 #6 Nov 26 2016 07:34:54
%S A169512 1,19,342,6156,110808,1994544,35901792,646232256,11632180608,
%T A169512 209379250944,3768826516992,67838877305856,1221099791505408,
%U A169512 21979796247097344,395636332447752192,7121453984059539456
%N A169512 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.
%C A169512 The initial terms coincide with those of A170738, although the two sequences are eventually different.
%C A169512 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169512 <a href="/index/Rec#order_34">Index entries for linear recurrences with constant coefficients</a>, signature (17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, -153).
%F A169512 G.f. (t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 +
%F A169512 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 +
%F A169512 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 +
%F A169512 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 +
%F A169512 2*t + 1)/(153*t^34 - 17*t^33 - 17*t^32 - 17*t^31 - 17*t^30 - 17*t^29 -
%F A169512 17*t^28 - 17*t^27 - 17*t^26 - 17*t^25 - 17*t^24 - 17*t^23 - 17*t^22 -
%F A169512 17*t^21 - 17*t^20 - 17*t^19 - 17*t^18 - 17*t^17 - 17*t^16 - 17*t^15 -
%F A169512 17*t^14 - 17*t^13 - 17*t^12 - 17*t^11 - 17*t^10 - 17*t^9 - 17*t^8 -
%F A169512 17*t^7 - 17*t^6 - 17*t^5 - 17*t^4 - 17*t^3 - 17*t^2 - 17*t + 1)
%K A169512 nonn
%O A169512 0,2
%A A169512 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009