cp's OEIS Frontend

A170212 Number of reduced words of length n in Coxeter group on 11 generators S_i with relations (S_i)^2 = (S_i S_j)^40 = I.

%I A170212 #8 Mar 22 2018 11:32:17
%S A170212 1,11,110,1100,11000,110000,1100000,11000000,110000000,1100000000,
%T A170212 11000000000,110000000000,1100000000000,11000000000000,
%U A170212 110000000000000,1100000000000000,11000000000000000,110000000000000000
%N A170212 Number of reduced words of length n in Coxeter group on 11 generators S_i with relations (S_i)^2 = (S_i S_j)^40 = I.
%C A170212 The initial terms coincide with those of A003953, although the two sequences are eventually different.
%C A170212 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170212 <a href="/index/Rec#order_40">Index entries for linear recurrences with constant coefficients</a>, signature (9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, -45).
%F A170212 G.f. (t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 +
%F A170212 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 + 2*t^25 +
%F A170212 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 + 2*t^17 +
%F A170212 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 +
%F A170212 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t +
%F A170212 1)/(45*t^40 - 9*t^39 - 9*t^38 - 9*t^37 - 9*t^36 - 9*t^35 - 9*t^34 -
%F A170212 9*t^33 - 9*t^32 - 9*t^31 - 9*t^30 - 9*t^29 - 9*t^28 - 9*t^27 - 9*t^26 -
%F A170212 9*t^25 - 9*t^24 - 9*t^23 - 9*t^22 - 9*t^21 - 9*t^20 - 9*t^19 - 9*t^18 -
%F A170212 9*t^17 - 9*t^16 - 9*t^15 - 9*t^14 - 9*t^13 - 9*t^12 - 9*t^11 - 9*t^10 -
%F A170212 9*t^9 - 9*t^8 - 9*t^7 - 9*t^6 - 9*t^5 - 9*t^4 - 9*t^3 - 9*t^2 - 9*t + 1)
%t A170212 coxG[{40,45,-9}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Mar 22 2018 *)
%K A170212 nonn
%O A170212 0,2
%A A170212 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009