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A166308
Number of reduced words of length n in Coxeter group on 47 generators S_i with relations (S_i)^2 = (S_i S_j)^10 = I.
1
1, 47, 2162, 99452, 4574792, 210440432, 9680259872, 445291954112, 20483429889152, 942237774900992, 43342937645444551, 1993775131690399620, 91713656057756096205, 4218828178656675254940, 194066096218202223884700
OFFSET
0,2
COMMENTS
The initial terms coincide with those of A170766, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
LINKS
Index entries for linear recurrences with constant coefficients, signature (45, 45, 45, 45, 45, 45, 45, 45, 45, -1035).
FORMULA
G.f.: (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 + 2*t + 1)/(1035*t^10 - 45*t^9 - 45*t^8 - 45*t^7 - 45*t^6 - 45*t^5 - 45*t^4 - 45*t^3 - 45*t^2 - 45*t + 1).
G.f.: (1+x)*(1-x^10)/(1 -46*x +1080*x^10 -1035*x^11). - G. C. Greubel, Apr 25 2019
MATHEMATICA
CoefficientList[Series[(1+x)*(1-x^10)/(1-46*x+1080*x^10-1035*x^11), {x, 0, 20}], x] (* G. C. Greubel, May 09 2016, modified Apr 25 2019 *)
coxG[{10, 1035, -45}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Aug 07 2017 *)
PROG
(PARI) my(x='x+O('x^20)); Vec((1+x)*(1-x^10)/(1-46*x+1080*x^10 -1035*x^11)) \\ G. C. Greubel, Apr 25 2019
(Magma) R<x>:=PowerSeriesRing(Integers(), 20); Coefficients(R!( (1+x)*(1-x^10)/(1-46*x+1080*x^10-1035*x^11) )); // G. C. Greubel, Apr 25 2019
(Sage) ((1+x)*(1-x^10)/(1-46*x+1080*x^10-1035*x^11)).series(x, 20).coefficients(x, sparse=False) # G. C. Greubel, Apr 25 2019
CROSSREFS
Sequence in context: A164692 A165179 A165703 * A166441 A166740 A167100
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 03 2009
STATUS
approved