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.

A159334 Transform of A056594 by the T_{1,1} transformation (see link).

Original entry on oeis.org

2, 4, 9, 23, 55, 126, 291, 678, 1578, 3667, 8523, 19815, 46066, 107089, 248950, 578740, 1345409, 3127695, 7271007, 16903042, 39294807, 91349342, 212361454, 493680487, 1147667895, 2668004163, 6202357186, 14418731129, 33519483178
Offset: 0

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Author

Richard Choulet, Apr 10 2009

Keywords

Crossrefs

Programs

  • Magma
    I:=[291, 678, 1578, 3667, 8523]; [2, 4, 9, 23, 55, 126] cat [n le 5 select I[n] else 3*Self(n-1) - 3*Self(n-2) + 4*Self(n-3) -2*Self(n-4) +Self(n-5): n in [1..50]]; // G. C. Greubel, Jun 25 2018
  • Mathematica
    Join[{2, 4, 9, 23, 55, 126}, LinearRecurrence[{3, -3, 4, -2, 1}, {291, 678, 1578, 3667, 8523}, 45]] (* G. C. Greubel, Jun 25 2018 *)
  • PARI
    x='x+O('x^50); Vec(-(2-2*x+3*x^2+x^4)/((x^2+1)*(x^3-2*x^2+3*x-1))) \\ G. C. Greubel, Jun 25 2018
    

Formula

O.g.f.: -(2-2*x+3*x^2+x^4)/((x^2+1)*(x^3-2*x^2+3*x-1)).
for n>=0 a(n+5)=3*a(n+4)-3*a(n+3)+4*a(n+2)-2*a(n+1)+a(n)