cp's OEIS Frontend

A170087 Number of reduced words of length n in Coxeter group on 30 generators S_i with relations (S_i)^2 = (S_i S_j)^37 = I.

%I A170087 #8 Nov 26 2016 10:05:43
%S A170087 1,30,870,25230,731670,21218430,615334470,17844699630,517496289270,
%T A170087 15007392388830,435214379276070,12621216999006030,366015292971174870,
%U A170087 10614443496164071230,307818861388758065670,8926746980273983904430
%N A170087 Number of reduced words of length n in Coxeter group on 30 generators S_i with relations (S_i)^2 = (S_i S_j)^37 = I.
%C A170087 The initial terms coincide with those of A170749, although the two sequences are eventually different.
%C A170087 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170087 <a href="/index/Rec#order_37">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, 28, 28, 28, -406).
%F A170087 G.f. (t^37 + 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 +
%F A170087 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 +
%F A170087 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 +
%F A170087 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 +
%F A170087 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(406*t^37 - 28*t^36 - 28*t^35 -
%F A170087 28*t^34 - 28*t^33 - 28*t^32 - 28*t^31 - 28*t^30 - 28*t^29 - 28*t^28 -
%F A170087 28*t^27 - 28*t^26 - 28*t^25 - 28*t^24 - 28*t^23 - 28*t^22 - 28*t^21 -
%F A170087 28*t^20 - 28*t^19 - 28*t^18 - 28*t^17 - 28*t^16 - 28*t^15 - 28*t^14 -
%F A170087 28*t^13 - 28*t^12 - 28*t^11 - 28*t^10 - 28*t^9 - 28*t^8 - 28*t^7 -
%F A170087 28*t^6 - 28*t^5 - 28*t^4 - 28*t^3 - 28*t^2 - 28*t + 1)
%t A170087 coxG[{37,406,-28}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Oct 03 2015 *)
%K A170087 nonn
%O A170087 0,2
%A A170087 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009