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.

A081584 Fourth row of Pascal-(1,2,1) array A081577.

Original entry on oeis.org

1, 13, 79, 307, 886, 2086, 4258, 7834, 13327, 21331, 32521, 47653, 67564, 93172, 125476, 165556, 214573, 273769, 344467, 428071, 526066, 640018, 771574, 922462, 1094491, 1289551, 1509613, 1756729, 2033032, 2340736, 2682136, 3059608
Offset: 0

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Author

Paul Barry, Mar 23 2003

Keywords

Comments

Equals binomial transform of [1, 12, 54, 108, 81, 0, 0, 0, ...] where (1, 12, 54, 108, 81) = row 4 of triangle A013610. - Gary W. Adamson, Jul 19 2008

Crossrefs

Programs

  • Magma
    [(8+6*n+81*n^2-18*n^3+27*n^4)/8: n in [0..40]]; // Vincenzo Librandi, Aug 09 2013
    
  • Maple
    seq((8+6*n+81*n^2-18*n^3+27*n^4)/8, n=0..40); # G. C. Greubel, May 26 2021
  • Mathematica
    CoefficientList[Series[(1+2x)^4/(1-x)^5, {x,0,40}], x] (* Vincenzo Librandi, Aug 09 2013 *)
    LinearRecurrence[{5,-10,10,-5,1},{1,13,79,307,886},40] (* Harvey P. Dale, Sep 18 2024 *)
  • Sage
    [(8+6*n+81*n^2-18*n^3+27*n^4)/8 for n in (0..40)] # G. C. Greubel, May 26 2021

Formula

a(n) = (8 + 6*n + 81*n^2 - 18*n^3 + 27*n^4)/8.
G.f.: (1+2*x)^4/(1-x)^5.
E.g.f.: (1/8)*(8 + 96*x + 216*x^2 + 144*x^3 + 27*x^4)*exp(x). - G. C. Greubel, May 26 2021