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.

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A135153 Repeat Pell numbers A000129.

Original entry on oeis.org

0, 0, 1, 1, 2, 2, 5, 5, 12, 12, 29, 29, 70, 70, 169, 169, 408, 408, 985, 985, 2378, 2378, 5741, 5741, 13860, 13860, 33461, 33461, 80782, 80782, 195025, 195025, 470832, 470832, 1136689, 1136689, 2744210, 2744210, 6625109, 6625109, 15994428, 15994428, 38613965
Offset: 0

Views

Author

Paul Curtz, Feb 14 2008

Keywords

Comments

The binomial transform is 0, 0, 1, 4, 12, 32,... (n>=0), i.e. A135248 without one of the leading zeros. - R. J. Mathar, Jul 10 2019

Programs

  • Magma
    I:=[0,0,1,1]; [n le 4 select I[n] else 2*Self(n-2)+Self(n-4): n in [1..50]]; // Vincenzo Librandi, Mar 03 2014
  • Mathematica
    CoefficientList[Series[x^2 (1 + x)/(1 - 2 x^2 - x^4), {x, 0, 50}], x] (* Vincenzo Librandi, Mar 03 2014 *)
    LinearRecurrence[{0,2,0,1},{0,0,1,1},50] (* Harvey P. Dale, May 28 2023 *)

Formula

G.f.: x^2*(1+x)/(1-2*x^2-x^4). - Philippe Deléham, Feb 25 2014
a(n) = 2*a(n-2) + a(n-4), a(0) = a(1) = 0, a(2) = a(3) = 1. - Philippe Deléham, Feb 25 2014

Extensions

Corrected and extended by Vincenzo Librandi, Mar 03 2014

A101893 a(n) = Sum_{k=0..floor(n/2)} C(n,2k)*Pell(k).

Original entry on oeis.org

0, 0, 1, 3, 8, 20, 50, 126, 320, 816, 2084, 5324, 13600, 34736, 88712, 226552, 578560, 1477504, 3773200, 9635888, 24607872, 62842944, 160486688, 409846752, 1046656000, 2672922880, 6826040896, 17432165568, 44517810688, 113688426240
Offset: 0

Views

Author

Paul Barry, Dec 22 2004

Keywords

Comments

Transform of Pell numbers under the mapping g(x)-> (1/(1-x))*g(x^2/((1-x)^2)).
Binomial transform of aerated Pell numbers 0,0,1,0,2,0,5,0,12,...

Crossrefs

Cf. A000129 (Pell numbers), A135248 (partial sums).

Programs

  • Mathematica
    CoefficientList[Series[x^2*(1-x)/(1 - 4*x + 4*x^2 - 2*x^4), {x, 0, 40}], x] (* Vaclav Kotesovec, Jan 05 2015 *)
    LinearRecurrence[{4,-4,0,2},{0,0,1,3},30] (* Harvey P. Dale, Aug 05 2018 *)

Formula

G.f.: x^2*(1-x)/(1 - 4*x + 4*x^2 - 2*x^4).
a(n) = 4*a(n-1) - 4*a(n-2) + 2*a(n-4).
a(n) = sum_{k=0..n} binomial(n, k) * A000129(k/2) * (1+(-1)^k)/2.
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