cp's OEIS Frontend

A170038 Number of reduced words of length n in Coxeter group on 29 generators S_i with relations (S_i)^2 = (S_i S_j)^36 = I.

%I A170038 #6 Nov 26 2016 09:45:04
%S A170038 1,29,812,22736,636608,17825024,499100672,13974818816,391294926848,
%T A170038 10956257951744,306775222648832,8589706234167296,240511774556684288,
%U A170038 6734329687587160064,188561231252440481792,5279714475068333490176
%N A170038 Number of reduced words of length n in Coxeter group on 29 generators S_i with relations (S_i)^2 = (S_i S_j)^36 = I.
%C A170038 The initial terms coincide with those of A170748, although the two sequences are eventually different.
%C A170038 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170038 <a href="/index/Rec#order_36">Index entries for linear recurrences with constant coefficients</a>, signature (27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, -378).
%F A170038 G.f. (t^36 + 2*t^35 + 2*t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 +
%F A170038 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 A170038 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 A170038 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 A170038 + 2*t^3 + 2*t^2 + 2*t + 1)/(378*t^36 - 27*t^35 - 27*t^34 - 27*t^33 -
%F A170038 27*t^32 - 27*t^31 - 27*t^30 - 27*t^29 - 27*t^28 - 27*t^27 - 27*t^26 -
%F A170038 27*t^25 - 27*t^24 - 27*t^23 - 27*t^22 - 27*t^21 - 27*t^20 - 27*t^19 -
%F A170038 27*t^18 - 27*t^17 - 27*t^16 - 27*t^15 - 27*t^14 - 27*t^13 - 27*t^12 -
%F A170038 27*t^11 - 27*t^10 - 27*t^9 - 27*t^8 - 27*t^7 - 27*t^6 - 27*t^5 - 27*t^4
%F A170038 - 27*t^3 - 27*t^2 - 27*t + 1)
%K A170038 nonn
%O A170038 0,2
%A A170038 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009