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.

A142585 Inverse binomial transform of A014217.

Original entry on oeis.org

1, 0, 1, 0, -1, 5, -14, 35, -81, 180, -389, 825, -1726, 3575, -7349, 15020, -30561, 61965, -125294, 252795, -509161, 1024100, -2057549, 4130225, -8284926, 16609455, -33282989, 66669660, -133507081, 267285605, -535010414, 1070731475, -2142612801, 4287086100
Offset: 0

Views

Author

Paul Curtz, Sep 21 2008

Keywords

Crossrefs

Programs

  • Magma
    [1] cat [(-1)^n*( Lucas(n) - 2^(n-1) ): n in [1..40]]; // G. C. Greubel, Apr 14 2021
    
  • Mathematica
    Table[(-1)^n*(LucasL[n] -2^(n-1)) - Boole[n==0]/2, {n,0,40}] (* G. C. Greubel, Apr 14 2021 *)
  • Sage
    [1]+[(-1)^n*( lucas_number2(n,1,-1) - 2^(n-1) ) for n in (1..40)] # G. C. Greubel, Apr 14 2021

Formula

a(n) = (-1)^(n+1) * A027974(n-4) for n > 4.
G.f.: (1+3*x+2*x^2+x^3)/((1+2*x)*(1+x-x^2)). - R. J. Mathar, Sep 22 2008
a(n) = (-1)^(n+1)*(2^(n-1) -F(n+1) -F(n-1)), where F(n) = A000045(n), for n>=1, with a(0)=1. - Johannes W. Meijer, Aug 15 2010
a(n) = -3*a(n-1) - a(n-2) + 2*a(n-3). - Wesley Ivan Hurt, Oct 06 2017

Extensions

Edited and extended by R. J. Mathar, Sep 22 2008