cp's OEIS Frontend

A169487 Number of reduced words of length n in Coxeter group on 42 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.

%I A169487 #6 Nov 26 2016 07:27:11
%S A169487 1,42,1722,70602,2894682,118681962,4865960442,199504378122,
%T A169487 8179679503002,335366859623082,13750041244546362,563751691026400842,
%U A169487 23113819332082434522,947666592615379815402,38854330297230572431482
%N A169487 Number of reduced words of length n in Coxeter group on 42 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.
%C A169487 The initial terms coincide with those of A170761, although the two sequences are eventually different.
%C A169487 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169487 <a href="/index/Rec#order_33">Index entries for linear recurrences with constant coefficients</a>, signature (40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, -820).
%F A169487 G.f. (t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 +
%F A169487 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 A169487 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 A169487 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 A169487 1)/(820*t^33 - 40*t^32 - 40*t^31 - 40*t^30 - 40*t^29 - 40*t^28 - 40*t^27
%F A169487 - 40*t^26 - 40*t^25 - 40*t^24 - 40*t^23 - 40*t^22 - 40*t^21 - 40*t^20 -
%F A169487 40*t^19 - 40*t^18 - 40*t^17 - 40*t^16 - 40*t^15 - 40*t^14 - 40*t^13 -
%F A169487 40*t^12 - 40*t^11 - 40*t^10 - 40*t^9 - 40*t^8 - 40*t^7 - 40*t^6 - 40*t^5
%F A169487 - 40*t^4 - 40*t^3 - 40*t^2 - 40*t + 1)
%K A169487 nonn
%O A169487 0,2
%A A169487 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009