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 A163526 Number of reduced words of length n in Coxeter group on 26 generators S_i with relations (S_i)^2 = (S_i S_j)^5 = I. 1
 1, 26, 650, 16250, 406250, 10155925, 253890000, 6347047200, 158671110000, 3966651000000, 99163106355300, 2478998445300000, 61972980856207200, 1549275016079700000, 38730637808401500000, 968235006358878382800 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The initial terms coincide with those of A170745, although the two sequences are eventually different. Computed with MAGMA using commands similar to those used to compute A154638. LINKS G. C. Greubel, Table of n, a(n) for n = 0..710 Index entries for linear recurrences with constant coefficients, signature (24, 24, 24, 24, -300). FORMULA G.f.: (t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(300*t^5 - 24*t^4 - 24*t^3 - 24*t^2 - 24*t + 1). MATHEMATICA CoefficientList[Series[(1+x)*(1-x^5)/(1-25*x+324*x^5-300*x^6), {x, 0, 20}], x] (* G. C. Greubel, Jul 27 2017 *) coxG[{5, 300, -24}] (* The coxG program is at A169452 *) (* G. C. Greubel, May 16 2019 *) PROG (PARI) my(x='x+O('x^20)); Vec((1+x)*(1-x^5)/(1-25*x+324*x^5-300*x^6)) \\ G. C. Greubel, Jul 27 2017 (MAGMA) R:=PowerSeriesRing(Integers(), 20); Coefficients(R!( (1+x)*(1-x^5)/(1-25*x+324*x^5-300*x^6) )); // G. C. Greubel, May 16 2019 (Sage) ((1+x)*(1-x^5)/(1-25*x+324*x^5-300*x^6)).series(x, 20).coefficients(x, sparse=False) # G. C. Greubel, May 16 2019 CROSSREFS Sequence in context: A106793 A162812 A163177 * A163995 A164639 A164964 Adjacent sequences:  A163523 A163524 A163525 * A163527 A163528 A163529 KEYWORD nonn AUTHOR John Cannon and N. J. A. Sloane, Dec 03 2009 STATUS approved

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Last modified August 17 11:06 EDT 2019. Contains 326057 sequences. (Running on oeis4.)