cp's OEIS Frontend

A170342 Number of reduced words of length n in Coxeter group on 45 generators S_i with relations (S_i)^2 = (S_i S_j)^42 = I.

%I A170342 #6 Nov 22 2016 08:26:27
%S A170342 1,45,1980,87120,3833280,168664320,7421230080,326534123520,
%T A170342 14367501434880,632170063134720,27815482777927680,1223881242228817920,
%U A170342 53850774658067988480,2369434084954991493120,104255099738019625697280
%N A170342 Number of reduced words of length n in Coxeter group on 45 generators S_i with relations (S_i)^2 = (S_i S_j)^42 = I.
%C A170342 The initial terms coincide with those of A170764, although the two sequences are eventually different.
%C A170342 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170342 <a href="/index/Rec#order_42">Index entries for linear recurrences with constant coefficients</a>, signature (43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, -946).
%F A170342 G.f. (t^42 + 2*t^41 + 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 +
%F A170342 2*t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 +
%F A170342 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 A170342 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 A170342 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 A170342 2*t + 1)/(946*t^42 - 43*t^41 - 43*t^40 - 43*t^39 - 43*t^38 - 43*t^37 -
%F A170342 43*t^36 - 43*t^35 - 43*t^34 - 43*t^33 - 43*t^32 - 43*t^31 - 43*t^30 -
%F A170342 43*t^29 - 43*t^28 - 43*t^27 - 43*t^26 - 43*t^25 - 43*t^24 - 43*t^23 -
%F A170342 43*t^22 - 43*t^21 - 43*t^20 - 43*t^19 - 43*t^18 - 43*t^17 - 43*t^16 -
%F A170342 43*t^15 - 43*t^14 - 43*t^13 - 43*t^12 - 43*t^11 - 43*t^10 - 43*t^9 -
%F A170342 43*t^8 - 43*t^7 - 43*t^6 - 43*t^5 - 43*t^4 - 43*t^3 - 43*t^2 - 43*t + 1)
%K A170342 nonn
%O A170342 0,2
%A A170342 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009