cp's OEIS Frontend

A170652 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^49 = I.

%I A170652 #6 Nov 21 2016 11:20:28
%S A170652 1,19,342,6156,110808,1994544,35901792,646232256,11632180608,
%T A170652 209379250944,3768826516992,67838877305856,1221099791505408,
%U A170652 21979796247097344,395636332447752192,7121453984059539456
%N A170652 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^49 = I.
%C A170652 The initial terms coincide with those of A170738, although the two sequences are eventually different.
%C A170652 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170652 <a href="/index/Rec#order_49">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, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, -153).
%F A170652 G.f. (t^49 + 2*t^48 + 2*t^47 + 2*t^46 + 2*t^45 + 2*t^44 + 2*t^43 + 2*t^42 +
%F A170652 2*t^41 + 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 +
%F A170652 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 +
%F A170652 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 +
%F A170652 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 +
%F A170652 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t +
%F A170652 1)/(153*t^49 - 17*t^48 - 17*t^47 - 17*t^46 - 17*t^45 - 17*t^44 - 17*t^43
%F A170652 - 17*t^42 - 17*t^41 - 17*t^40 - 17*t^39 - 17*t^38 - 17*t^37 - 17*t^36 -
%F A170652 17*t^35 - 17*t^34 - 17*t^33 - 17*t^32 - 17*t^31 - 17*t^30 - 17*t^29 -
%F A170652 17*t^28 - 17*t^27 - 17*t^26 - 17*t^25 - 17*t^24 - 17*t^23 - 17*t^22 -
%F A170652 17*t^21 - 17*t^20 - 17*t^19 - 17*t^18 - 17*t^17 - 17*t^16 - 17*t^15 -
%F A170652 17*t^14 - 17*t^13 - 17*t^12 - 17*t^11 - 17*t^10 - 17*t^9 - 17*t^8 -
%F A170652 17*t^7 - 17*t^6 - 17*t^5 - 17*t^4 - 17*t^3 - 17*t^2 - 17*t + 1)
%K A170652 nonn
%O A170652 0,2
%A A170652 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009