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.

A374917 Inverse of the Fibonacci sequence beginning 1,1 with respect to binomial convolution.

Original entry on oeis.org

1, -1, 0, 3, -5, -18, 113, 35, -3044, 9755, 87999, -882894, -1155935, 69780087, -292042360, -5040306157, 64613044147, 197030202470, -10570955773551, 48865639709115, 1470783141900676, -21819085085811861, -123330624543827305, 6244177033369108298, -28216305335425392575, -1453926618188019546193
Offset: 0

Views

Author

Fernando Miranda, Maria Irene Falcao and Goncalo Carvalho, Jul 23 2024

Keywords

Comments

The binomial convolution of this sequence with the Fibonacci sequence beginning 1,1 gives the identity sequence with respect to convolution (A000007).

Crossrefs

Programs

  • Maple
    p:=(1-sqrt(5))/2: q:=(1+sqrt(5))/2:
    egf := (1-2*q)/(p*exp(p*x)-q*exp(q*x)): ser := series(egf, x, 27):
    seq(n!*simplify(coeff(ser, x, n)), n=0..25); # Peter Luschny, Aug 05 2024
  • Mathematica
    a[0] = 1; a[n_]:=a[n]= -Sum[Binomial[n, k] Fibonacci[k + 1] a[n - k], {k, 1, n}]
    (* or, to generate the list L of the first n terms *)
    phi = (1 + Sqrt[5])/2; psi = 1 - phi; L[n_] := CoefficientList[Series[(phi - psi)/(phi Exp[phi x] - psi Exp[psi x]), {x, 0, n}], x] Table[k!, {k, 0, n}]

Formula

a(0) = 1, a(n) = -Sum_{k=1..n} binomial(n, k)*a(n - k)*A000045(k+1).
E.g.f.: 1/G'(x) where G(x) is the e.g.f. of A000045.
The recursion P(0, x) = 1, P(n, x) = x^n - Sum_{k=0..n-1} binomial(n, k)*a(n-k)*P(k, x) defines the so-called Appell-Fibonacci polynomials P(n, x) = Sum_{k=0..n} T(n, k)*x^k, where T(n, k) is the triangular array A094436.