cp's OEIS Frontend

A169523 Number of reduced words of length n in Coxeter group on 30 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.

%I A169523 #8 Nov 26 2016 07:38:00
%S A169523 1,30,870,25230,731670,21218430,615334470,17844699630,517496289270,
%T A169523 15007392388830,435214379276070,12621216999006030,366015292971174870,
%U A169523 10614443496164071230,307818861388758065670,8926746980273983904430
%N A169523 Number of reduced words of length n in Coxeter group on 30 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.
%C A169523 The initial terms coincide with those of A170749, although the two sequences are eventually different.
%C A169523 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169523 <a href="/index/Rec#order_34">Index entries for linear recurrences with constant coefficients</a>, signature (28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, -406).
%F A169523 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 A169523 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 A169523 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 A169523 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 A169523 2*t + 1)/(406*t^34 - 28*t^33 - 28*t^32 - 28*t^31 - 28*t^30 - 28*t^29 -
%F A169523 28*t^28 - 28*t^27 - 28*t^26 - 28*t^25 - 28*t^24 - 28*t^23 - 28*t^22 -
%F A169523 28*t^21 - 28*t^20 - 28*t^19 - 28*t^18 - 28*t^17 - 28*t^16 - 28*t^15 -
%F A169523 28*t^14 - 28*t^13 - 28*t^12 - 28*t^11 - 28*t^10 - 28*t^9 - 28*t^8 -
%F A169523 28*t^7 - 28*t^6 - 28*t^5 - 28*t^4 - 28*t^3 - 28*t^2 - 28*t + 1)
%t A169523 coxG[{34,406,-28}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Aug 25 2014 *)
%K A169523 nonn
%O A169523 0,2
%A A169523 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009