cp's OEIS Frontend

A169506 Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.

%I A169506 #8 Jul 09 2017 11:48:05
%S A169506 1,13,156,1872,22464,269568,3234816,38817792,465813504,5589762048,
%T A169506 67077144576,804925734912,9659108818944,115909305827328,
%U A169506 1390911669927936,16690940039135232,200291280469622784
%N A169506 Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^34 = I.
%C A169506 The initial terms coincide with those of A170732, although the two sequences are eventually different.
%C A169506 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169506 <a href="/index/Rec#order_34">Index entries for linear recurrences with constant coefficients</a>, signature (11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, -66).
%F A169506 G.f. (t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 +
%F A169506 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 +
%F A169506 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 +
%F A169506 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 +
%F A169506 2*t + 1)/(66*t^34 - 11*t^33 - 11*t^32 - 11*t^31 - 11*t^30 - 11*t^29 -
%F A169506 11*t^28 - 11*t^27 - 11*t^26 - 11*t^25 - 11*t^24 - 11*t^23 - 11*t^22 -
%F A169506 11*t^21 - 11*t^20 - 11*t^19 - 11*t^18 - 11*t^17 - 11*t^16 - 11*t^15 -
%F A169506 11*t^14 - 11*t^13 - 11*t^12 - 11*t^11 - 11*t^10 - 11*t^9 - 11*t^8 -
%F A169506 11*t^7 - 11*t^6 - 11*t^5 - 11*t^4 - 11*t^3 - 11*t^2 - 11*t + 1)
%t A169506 coxG[{34,66,-11}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jul 09 2017 *)
%K A169506 nonn
%O A169506 0,2
%A A169506 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009