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 A007788 Number of augmented Andre 3-signed permutations: E.g.f. (1-sin(3*x))^(-1/3). 8
 1, 1, 4, 19, 136, 1201, 13024, 165619, 2425216, 40132801, 740882944, 15091932019, 336257744896, 8134269015601, 212309523595264, 5946914908771219, 177934946000306176, 5663754614516217601 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS It appears that all members are of the form 3k+1. - Ralf Stephan, Nov 12 2007 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 R. Ehrenborg and M. A. Readdy, Sheffer posets and r-signed permutations, Preprint submitted to Ann. Sci. Math. Quebec, 1994. (Annotated scanned copy) R. Ehrenborg and M. A. Readdy, Sheffer posets and r-signed permutations, Ann. Sci. Math. Québec, 19 (1995), no. 2, 173-196. R. Ehrenborg and M. A. Readdy, The r-cubical lattice and a generalization of the cd-index, European J. Combin. 17 (1996), no. 8, 709-725. FORMULA E.g.f.: (1-sin(3*x))^(-1/3). a(n) ~ n! * 2*6^n/(Pi^(n+2/3)*n^(1/3)*Gamma(2/3)). - Vaclav Kotesovec, Jun 25 2013 MAPLE m:=20; S:=series( (1-sin(3*x))^(-1/3), x, m+1): seq(j!*coeff(S, x, j), j=0..m); # G. C. Greubel, Mar 05 2020 MATHEMATICA With[{nn=20}, CoefficientList[Series[(1-Sin[3x])^(-1/3), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Nov 23 2011 *) PROG (PARI) Vec(serlaplace( (1-sin(3*x))^(-1/3) +O('x^20) )) \\ G. C. Greubel, Mar 05 2020 (MAGMA) R:=PowerSeriesRing(Rationals(), 20); Coefficients(R!(Laplace( (1-Sin(3*x))^(-1/3) ))); // G. C. Greubel, Mar 05 2020 (Sage) m=20; def A007788_list(prec):     P. = PowerSeriesRing(QQ, prec)     return P( (1-sin(3*x))^(-1/3) ).list() a=A007788_list(m+1); [factorial(n)*a[n] for n in (0..m)] # G. C. Greubel, Mar 05 2020 CROSSREFS Cf. A007863, A235135, A235132. Sequence in context: A134147 A220066 A157303 * A259354 A215851 A197920 Adjacent sequences:  A007785 A007786 A007787 * A007789 A007790 A007791 KEYWORD nonn AUTHOR R. Ehrenborg (ehrenbor(AT)lacim.uqam.ca) and M. A. Readdy (readdy(AT)lacim.uqam.ca) STATUS approved

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Last modified December 2 14:09 EST 2021. Contains 349445 sequences. (Running on oeis4.)