cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A055854 Convolution of A055853 with A011782.

Original entry on oeis.org

0, 1, 9, 53, 253, 1059, 4043, 14407, 48639, 157184, 489872, 1480608, 4358752, 12541184, 35364864, 97960192, 267050240, 717619200, 1903452160, 4989337600, 12937052160, 33212530688, 84484882432, 213090238464, 533236219904
Offset: 0

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Author

Wolfdieter Lang May 30 2000

Keywords

Comments

Ninth column of triangle A055587.
T(n,7) of array T as in A049600.

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 30); [0] cat Coefficients(R!( x*(1-x)^7/(1-2*x)^8 )); // G. C. Greubel, Jan 16 2020
    
  • Maple
    seq(coeff(series(x*(1-x)^7/(1-2*x)^8, x, n+1), x, n), n = 0..30); # G. C. Greubel, Jan 16 2020
  • Mathematica
    CoefficientList[Series[x*(1-x)^7/(1-2*x)^8, {x,0,30}], x] (* G. C. Greubel, Jan 16 2020 *)
    LinearRecurrence[{16,-112,448,-1120,1792,-1792,1024,-256},{0,1,9,53,253,1059,4043,14407,48639,157184},40] (* Harvey P. Dale, Nov 04 2023 *)
  • PARI
    my(x='x+O('x^30)); concat([0], Vec(x*(1-x)^7/(1-2*x)^8)) \\ G. C. Greubel, Jan 16 2020
    
  • Sage
    def A055854_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( x*(1-x)^7/(1-2*x)^8 ).list()
    A055854_list(30) # G. C. Greubel, Jan 16 2020

Formula

a(n)= T(n, 7)= A055587(n+7, 8).
G.f.: x*(1-x)^7/(1-2*x)^8.