cp's OEIS Frontend

A170225 Number of reduced words of length n in Coxeter group on 24 generators S_i with relations (S_i)^2 = (S_i S_j)^40 = I.

%I A170225 #8 Nov 22 2016 15:22:01
%S A170225 1,24,552,12696,292008,6716184,154472232,3552861336,81715810728,
%T A170225 1879463646744,43227663875112,994236269127576,22867434189934248,
%U A170225 525950986368487704,12096872686475217192,278228071788929995416
%N A170225 Number of reduced words of length n in Coxeter group on 24 generators S_i with relations (S_i)^2 = (S_i S_j)^40 = I.
%C A170225 The initial terms coincide with those of A170743, although the two sequences are eventually different.
%C A170225 Computed with MAGMA using commands similar to those used to compute A154638.
%H A170225 <a href="/index/Rec#order_40">Index entries for linear recurrences with constant coefficients</a>, signature (22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, -253).
%F A170225 G.f. (t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 +
%F A170225 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 A170225 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 A170225 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 A170225 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t +
%F A170225 1)/(253*t^40 - 22*t^39 - 22*t^38 - 22*t^37 - 22*t^36 - 22*t^35 - 22*t^34
%F A170225 - 22*t^33 - 22*t^32 - 22*t^31 - 22*t^30 - 22*t^29 - 22*t^28 - 22*t^27 -
%F A170225 22*t^26 - 22*t^25 - 22*t^24 - 22*t^23 - 22*t^22 - 22*t^21 - 22*t^20 -
%F A170225 22*t^19 - 22*t^18 - 22*t^17 - 22*t^16 - 22*t^15 - 22*t^14 - 22*t^13 -
%F A170225 22*t^12 - 22*t^11 - 22*t^10 - 22*t^9 - 22*t^8 - 22*t^7 - 22*t^6 - 22*t^5
%F A170225 - 22*t^4 - 22*t^3 - 22*t^2 - 22*t + 1)
%t A170225 coxG[{40,253,-22}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jan 09 2016 *)
%K A170225 nonn
%O A170225 0,2
%A A170225 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009