cp's OEIS Frontend

A170367 Number of reduced words of length n in Coxeter group on 22 generators S_i with relations (S_i)^2 = (S_i S_j)^43 = I.

%I A170367 #8 Jul 24 2017 20:12:05
%S A170367 1,22,462,9702,203742,4278582,89850222,1886854662,39623947902,
%T A170367 832102905942,17474161024782,366957381520422,7706105011928862,
%U A170367 161828205250506102,3398392310260628142,71366238515473190982
%N A170367 Number of reduced words of length n in Coxeter group on 22 generators S_i with relations (S_i)^2 = (S_i S_j)^43 = I.
%C A170367 The initial terms coincide with those of A170741, although the two sequences are eventually different.
%C A170367 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170367 <a href="/index/Rec#order_43">Index entries for linear recurrences with constant coefficients</a>, signature (20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, -210).
%F A170367 G.f. (t^43 + 2*t^42 + 2*t^41 + 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 +
%F A170367 2*t^35 + 2*t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 +
%F A170367 2*t^27 + 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 +
%F A170367 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 +
%F A170367 2*t^11 + 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3
%F A170367 + 2*t^2 + 2*t + 1)/(210*t^43 - 20*t^42 - 20*t^41 - 20*t^40 - 20*t^39 -
%F A170367 20*t^38 - 20*t^37 - 20*t^36 - 20*t^35 - 20*t^34 - 20*t^33 - 20*t^32 -
%F A170367 20*t^31 - 20*t^30 - 20*t^29 - 20*t^28 - 20*t^27 - 20*t^26 - 20*t^25 -
%F A170367 20*t^24 - 20*t^23 - 20*t^22 - 20*t^21 - 20*t^20 - 20*t^19 - 20*t^18 -
%F A170367 20*t^17 - 20*t^16 - 20*t^15 - 20*t^14 - 20*t^13 - 20*t^12 - 20*t^11 -
%F A170367 20*t^10 - 20*t^9 - 20*t^8 - 20*t^7 - 20*t^6 - 20*t^5 - 20*t^4 - 20*t^3 -
%F A170367 20*t^2 - 20*t + 1)
%t A170367 coxG[{43,210,-20}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jul 24 2017 *)
%K A170367 nonn
%O A170367 0,2
%A A170367 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009