login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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<x>:=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.<x> = 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

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