cp's OEIS Frontend

A170022 Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^36 = I.

%I A170022 #8 Aug 29 2017 16:06:52
%S A170022 1,13,156,1872,22464,269568,3234816,38817792,465813504,5589762048,
%T A170022 67077144576,804925734912,9659108818944,115909305827328,
%U A170022 1390911669927936,16690940039135232,200291280469622784
%N A170022 Number of reduced words of length n in Coxeter group on 13 generators S_i with relations (S_i)^2 = (S_i S_j)^36 = I.
%C A170022 The initial terms coincide with those of A170732, although the two sequences are eventually different.
%C A170022 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170022 <a href="/index/Rec#order_36">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, 11, 11, -66).
%F A170022 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 A170022 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 A170022 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 A170022 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 A170022 + 2*t^3 + 2*t^2 + 2*t + 1)/(66*t^36 - 11*t^35 - 11*t^34 - 11*t^33 -
%F A170022 11*t^32 - 11*t^31 - 11*t^30 - 11*t^29 - 11*t^28 - 11*t^27 - 11*t^26 -
%F A170022 11*t^25 - 11*t^24 - 11*t^23 - 11*t^22 - 11*t^21 - 11*t^20 - 11*t^19 -
%F A170022 11*t^18 - 11*t^17 - 11*t^16 - 11*t^15 - 11*t^14 - 11*t^13 - 11*t^12 -
%F A170022 11*t^11 - 11*t^10 - 11*t^9 - 11*t^8 - 11*t^7 - 11*t^6 - 11*t^5 - 11*t^4
%F A170022 - 11*t^3 - 11*t^2 - 11*t + 1)
%t A170022 coxG[{36,66,-11}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Aug 29 2017 *)
%K A170022 nonn
%O A170022 0,2
%A A170022 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009