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.

A134393 Row sums of triangle A134392.

Original entry on oeis.org

1, 3, 8, 20, 45, 91, 168, 288, 465, 715, 1056, 1508, 2093, 2835, 3760, 4896, 6273, 7923, 9880, 12180, 14861, 17963, 21528, 25600, 30225, 35451, 41328, 47908, 55245, 63395, 72416, 82368, 93313, 105315, 118440, 132756, 148333, 165243, 183560, 203360, 224721, 247723, 272448
Offset: 1

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Author

Gary W. Adamson, Oct 23 2007

Keywords

Comments

Binomial transform of [1, 2, 3, 4, 2, 0, 0, 0, ...].
The Kn4 triangle sums of A139600 are given by this sequence. For the definitions of the Kn4 and other triangle sums see A180662. - Johannes W. Meijer, Apr 29 2011

Examples

			a(4) = 20 = (1, 3, 3, 1) dot (1, 2, 3, 4) = (1 + 6 + 9 + 4).
a(4) = sum of row 4 terms of triangle A134392: (8 + 7 + 4 + 1).
		

Crossrefs

Programs

  • Magma
    [Binomial(n+3, 4)-2*Binomial(n+2, 4)+ 3*Binomial(n+1, 4): n in [1..40]]; // Vincenzo Librandi, Feb 04 2013
    
  • Mathematica
    Table[(n^4 - 2*n^3 + 5*n^2 + 8*n)/12, {n, 1, 40}] (* Vincenzo Librandi, Feb 04 2013 *)
    LinearRecurrence[{5,-10,10,-5,1},{1,3,8,20,45},50] (* Harvey P. Dale, May 28 2018 *)
  • PARI
    x='x+O('x^99); Vec(x*(1-2*x+3*x^2)/(1-x)^5) \\ Altug Alkan, Aug 16 2017

Formula

From R. J. Mathar, Jun 08 2008: (Start)
O.g.f.: x*(1-2*x+3*x^2)/(1-x)^5.
a(n) = A014628(n+1). (End)
a(n) = binomial(n+3,4) - 2*binomial(n+2,4) + 3*binomial(n+1,4). - Johannes W. Meijer, Apr 29 2011, corrected by Eric Rowland, Aug 16 2017
a(n) = n*(n + 1)*(n^2 - 3*n + 8)/12. - Johannes W. Meijer, Apr 29 2011, corrected by Eric Rowland, Aug 16 2017