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.

A014286 a(n) = Sum_{j=0..n} j*Fibonacci(j).

Original entry on oeis.org

0, 1, 3, 9, 21, 46, 94, 185, 353, 659, 1209, 2188, 3916, 6945, 12223, 21373, 37165, 64314, 110826, 190265, 325565, 555431, 945073, 1604184, 2717016, 4592641, 7748859, 13052145, 21950853, 36863494, 61824694, 103559033, 173264921, 289575995, 483474153
Offset: 0

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Comments

Equals row sums of triangle A143061. - Gary W. Adamson, Jul 20 2008

Crossrefs

Cf. A000045.
Cf. A143061.
Partial sums of A045925.
Cf. A282464: partial sums of j*Fibonacci(j)^2.

Programs

  • GAP
    List([0..50], n-> n*Fibonacci(n+2)-Fibonacci(n+3)+2); # G. C. Greubel, Jun 13 2019
  • Magma
    [n*Fibonacci(n+2)-Fibonacci(n+3)+2: n in [0..50]]; // Vincenzo Librandi, Mar 31 2011
    
  • Maple
    A014286 := proc(n)
        add(i*combinat[fibonacci](i),i=0..n) ;
    end proc: # R. J. Mathar, Apr 11 2016
  • Mathematica
    Accumulate[Table[Fibonacci[n]*n, {n, 0, 50}]] (* Vladimir Joseph Stephan Orlovsky, Jun 28 2011 *)
    a[0] = 0; a[1] = 1; a[2] = 3; a[3] = 9; a[n_] := a[n] = 2 a[n-1] + a[n-2] - 2 a[n-3] - a[n-4] + 2; Table[a[n], {n, 0, 50}] (* Vladimir Reshetnikov, Oct 28 2015 *)
  • PARI
    concat(0, Vec(x*(1+x^2)/((1-x)*(1-x-x^2)^2) + O(x^50))) \\ Altug Alkan, Oct 28 2015
    
  • Sage
    [n*fibonacci(n+2)-fibonacci(n+3)+2 for n in (0..50)] # G. C. Greubel, Jun 13 2019
    

Formula

G.f.: x*(1+x^2)/((1-x)*(1-x-x^2)^2).
a(n) = n*F(n+2) - F(n+3) + 2.
Recurrences, from Vladimir Reshetnikov, Oct 28 2015: (Start)
6-term, homogeneous, constant coefficients: a(0) = 0, a(1) = 1, a(2) = 3, a(3) = 9, a(4) = 21, a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + a(n-4) + a(n-5).
5-term, non-homogeneous, constant coefficients: a(0) = 0, a(1) = 1, a(2) = 3, a(3) = 9, a(n) = 2*a(n-1) + a(n-2) - 2*a(n-3) - a(n-4) + 2. (End)