cp's OEIS Frontend

A170421 Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^44 = I.

%I A170421 #8 Mar 22 2020 11:28:22
%S A170421 1,28,756,20412,551124,14880348,401769396,10847773692,292889889684,
%T A170421 7908027021468,213516729579636,5764951698650172,155653695863554644,
%U A170421 4202649788315975388,113471544284531335476,3063731695682346057852
%N A170421 Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^44 = I.
%C A170421 The initial terms coincide with those of A170747, although the two sequences are eventually different.
%C A170421 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170421 <a href="/index/Rec#order_44">Index entries for linear recurrences with constant coefficients</a>, signature (26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, -351).
%F A170421 G.f. (t^44 + 2*t^43 + 2*t^42 + 2*t^41 + 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 +
%F A170421 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 +
%F A170421 2*t^28 + 2*t^27 + 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 +
%F A170421 2*t^20 + 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 +
%F A170421 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4
%F A170421 + 2*t^3 + 2*t^2 + 2*t + 1)/(351*t^44 - 26*t^43 - 26*t^42 - 26*t^41 -
%F A170421 26*t^40 - 26*t^39 - 26*t^38 - 26*t^37 - 26*t^36 - 26*t^35 - 26*t^34 -
%F A170421 26*t^33 - 26*t^32 - 26*t^31 - 26*t^30 - 26*t^29 - 26*t^28 - 26*t^27 -
%F A170421 26*t^26 - 26*t^25 - 26*t^24 - 26*t^23 - 26*t^22 - 26*t^21 - 26*t^20 -
%F A170421 26*t^19 - 26*t^18 - 26*t^17 - 26*t^16 - 26*t^15 - 26*t^14 - 26*t^13 -
%F A170421 26*t^12 - 26*t^11 - 26*t^10 - 26*t^9 - 26*t^8 - 26*t^7 - 26*t^6 - 26*t^5
%F A170421 - 26*t^4 - 26*t^3 - 26*t^2 - 26*t + 1)
%t A170421 coxG[{44,351,-26}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Mar 22 2020 *)
%K A170421 nonn
%O A170421 0,2
%A A170421 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009