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.

A010901 Pisot sequences E(4,7), P(4,7).

Original entry on oeis.org

4, 7, 12, 21, 37, 65, 114, 200, 351, 616, 1081, 1897, 3329, 5842, 10252, 17991, 31572, 55405, 97229, 170625, 299426, 525456, 922111, 1618192, 2839729, 4983377, 8745217, 15346786, 26931732, 47261895, 82938844, 145547525, 255418101, 448227521, 786584466
Offset: 0

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Keywords

Comments

Essentially the same as A005251: a(n) = A005251(n+5).
See A008776 for definitions of Pisot sequences.

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{2, -1, 1}, {4, 7, 12}, 35] (* Jean-François Alcover, Oct 05 2018 *)
  • PARI
    pisotE(nmax, a1, a2) = {
      a=vector(nmax); a[1]=a1; a[2]=a2;
      for(n=3, nmax, a[n] = floor(a[n-1]^2/a[n-2]+1/2));
      a
    }
    pisotE(50, 4, 7) \\ Colin Barker, Jul 27 2016

Formula

a(n) = 2a(n-1) - a(n-2) + a(n-3) for n>=3. (Proved using the PtoRv program of Ekhad-Sloane-Zeilberger.) - N. J. A. Sloane, Sep 09 2016

Extensions

Edited by N. J. A. Sloane, Jul 26 2016