cp's OEIS Frontend

A170277 Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^41 = I.

%I A170277 #8 Dec 12 2016 19:00:29
%S A170277 1,28,756,20412,551124,14880348,401769396,10847773692,292889889684,
%T A170277 7908027021468,213516729579636,5764951698650172,155653695863554644,
%U A170277 4202649788315975388,113471544284531335476,3063731695682346057852
%N A170277 Number of reduced words of length n in Coxeter group on 28 generators S_i with relations (S_i)^2 = (S_i S_j)^41 = I.
%C A170277 The initial terms coincide with those of A170747, although the two sequences are eventually different.
%C A170277 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170277 <a href="/index/Rec#order_41">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, -351).
%F A170277 G.f. (t^41 + 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 +
%F A170277 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 A170277 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 A170277 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 A170277 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 A170277 1)/(351*t^41 - 26*t^40 - 26*t^39 - 26*t^38 - 26*t^37 - 26*t^36 - 26*t^35
%F A170277 - 26*t^34 - 26*t^33 - 26*t^32 - 26*t^31 - 26*t^30 - 26*t^29 - 26*t^28 -
%F A170277 26*t^27 - 26*t^26 - 26*t^25 - 26*t^24 - 26*t^23 - 26*t^22 - 26*t^21 -
%F A170277 26*t^20 - 26*t^19 - 26*t^18 - 26*t^17 - 26*t^16 - 26*t^15 - 26*t^14 -
%F A170277 26*t^13 - 26*t^12 - 26*t^11 - 26*t^10 - 26*t^9 - 26*t^8 - 26*t^7 -
%F A170277 26*t^6 - 26*t^5 - 26*t^4 - 26*t^3 - 26*t^2 - 26*t + 1)
%t A170277 coxG[{41,351,-26}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Dec 12 2016 *)
%K A170277 nonn
%O A170277 0,2
%A A170277 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009