cp's OEIS Frontend

A170655 Number of reduced words of length n in Coxeter group on 22 generators S_i with relations (S_i)^2 = (S_i S_j)^49 = I.

%I A170655 #6 Nov 21 2016 11:22:35
%S A170655 1,22,462,9702,203742,4278582,89850222,1886854662,39623947902,
%T A170655 832102905942,17474161024782,366957381520422,7706105011928862,
%U A170655 161828205250506102,3398392310260628142,71366238515473190982
%N A170655 Number of reduced words of length n in Coxeter group on 22 generators S_i with relations (S_i)^2 = (S_i S_j)^49 = I.
%C A170655 The initial terms coincide with those of A170741, although the two sequences are eventually different.
%C A170655 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170655 <a href="/index/Rec#order_49">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, 20, 20, 20, 20, 20, 20, -210).
%F A170655 G.f. (t^49 + 2*t^48 + 2*t^47 + 2*t^46 + 2*t^45 + 2*t^44 + 2*t^43 + 2*t^42 +
%F A170655 2*t^41 + 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 +
%F A170655 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 +
%F A170655 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 A170655 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 A170655 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 A170655 1)/(210*t^49 - 20*t^48 - 20*t^47 - 20*t^46 - 20*t^45 - 20*t^44 - 20*t^43
%F A170655 - 20*t^42 - 20*t^41 - 20*t^40 - 20*t^39 - 20*t^38 - 20*t^37 - 20*t^36 -
%F A170655 20*t^35 - 20*t^34 - 20*t^33 - 20*t^32 - 20*t^31 - 20*t^30 - 20*t^29 -
%F A170655 20*t^28 - 20*t^27 - 20*t^26 - 20*t^25 - 20*t^24 - 20*t^23 - 20*t^22 -
%F A170655 20*t^21 - 20*t^20 - 20*t^19 - 20*t^18 - 20*t^17 - 20*t^16 - 20*t^15 -
%F A170655 20*t^14 - 20*t^13 - 20*t^12 - 20*t^11 - 20*t^10 - 20*t^9 - 20*t^8 -
%F A170655 20*t^7 - 20*t^6 - 20*t^5 - 20*t^4 - 20*t^3 - 20*t^2 - 20*t + 1)
%K A170655 nonn
%O A170655 0,2
%A A170655 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009