cp's OEIS Frontend

A170626 Number of reduced words of length n in Coxeter group on 41 generators S_i with relations (S_i)^2 = (S_i S_j)^48 = I.

%I A170626 #6 Nov 21 2016 12:21:09
%S A170626 1,41,1640,65600,2624000,104960000,4198400000,167936000000,
%T A170626 6717440000000,268697600000000,10747904000000000,429916160000000000,
%U A170626 17196646400000000000,687865856000000000000,27514634240000000000000
%N A170626 Number of reduced words of length n in Coxeter group on 41 generators S_i with relations (S_i)^2 = (S_i S_j)^48 = I.
%C A170626 The initial terms coincide with those of A170760, although the two sequences are eventually different.
%C A170626 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170626 <a href="/index/Rec#order_48">Index entries for linear recurrences with constant coefficients</a>, signature (39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, -780).
%F A170626 G.f. (t^48 + 2*t^47 + 2*t^46 + 2*t^45 + 2*t^44 + 2*t^43 + 2*t^42 + 2*t^41 +
%F A170626 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 +
%F A170626 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 A170626 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 A170626 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 A170626 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t +
%F A170626 1)/(780*t^48 - 39*t^47 - 39*t^46 - 39*t^45 - 39*t^44 - 39*t^43 - 39*t^42
%F A170626 - 39*t^41 - 39*t^40 - 39*t^39 - 39*t^38 - 39*t^37 - 39*t^36 - 39*t^35 -
%F A170626 39*t^34 - 39*t^33 - 39*t^32 - 39*t^31 - 39*t^30 - 39*t^29 - 39*t^28 -
%F A170626 39*t^27 - 39*t^26 - 39*t^25 - 39*t^24 - 39*t^23 - 39*t^22 - 39*t^21 -
%F A170626 39*t^20 - 39*t^19 - 39*t^18 - 39*t^17 - 39*t^16 - 39*t^15 - 39*t^14 -
%F A170626 39*t^13 - 39*t^12 - 39*t^11 - 39*t^10 - 39*t^9 - 39*t^8 - 39*t^7 -
%F A170626 39*t^6 - 39*t^5 - 39*t^4 - 39*t^3 - 39*t^2 - 39*t + 1)
%K A170626 nonn
%O A170626 0,2
%A A170626 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009