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.

A159343 Transform of A056594 by the T_{0,1} transformation (see link).

Original entry on oeis.org

2, 3, 6, 16, 39, 89, 205, 478, 1113, 2586, 6010, 13973, 32485, 75517, 175554, 408115, 948754, 2205584, 5127359, 11919665, 27709861, 64417610, 149752773, 348132962, 809310950, 1881419697, 4373770153, 10167782017, 23637225442, 54949882443
Offset: 0

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Author

Richard Choulet, Apr 11 2009

Keywords

Crossrefs

Programs

  • Magma
    I:=[2, 3, 6, 16, 39]; [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 17 2018
  • Maple
    a(0):=2: a(1):=3:a(2):=6: a(3):=16:a(4):=39:for n from 0 to 31 do a(n+5):=3*a(n+4)-3*a(n+3)+4*a(n+2)-2*a(n+1)+a(n):od:seq(a(i),i=0..31);
  • Mathematica
    LinearRecurrence[{3, -3, 4, -2, 1}, {2, 3, 6, 16, 39}, 50] (* G. C. Greubel, Jun 17 2018 *)
  • PARI
    m=32; v=concat([2, 3, 6, 16, 39], vector(m-5)); for(n=6, m, v[n] = 3*v[n-1] -3*v[n-2] +4*v[n-3] -2*v[n-4] +v[n-5]); v \\ G. C. Greubel, Jun 17 2018
    

Formula

O.g.f.: ((1-z)^2/(1-3*z+2*z^2-z^3))*(1/(1+z^2))+((1-z+z^2)/(1-3*z+2*z^2-z^3)).
a(n) = 3*a(n-1) - 3*a(n-2) + 4*a(n-3) - 2*a(n-4) + a(n-5) for n>=5, with a(0)=2, a(1)=3, a(2)=6, a(3)=16, a(4)=39.