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.

A143131 Binomial transform of [1, 4, 10, 20, 0, 0, 0, ...].

Original entry on oeis.org

1, 5, 19, 63, 157, 321, 575, 939, 1433, 2077, 2891, 3895, 5109, 6553, 8247, 10211, 12465, 15029, 17923, 21167, 24781, 28785, 33199, 38043, 43337, 49101, 55355, 62119, 69413, 77257, 85671, 94675, 104289, 114533, 125427, 136991, 149245
Offset: 1

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Author

Gary W. Adamson, Jul 27 2008

Keywords

Examples

			a(4) = 63 = (1, 3, 3, 1) dot (1, 4, 10, 20) = (1 + 12 + 30 + 20).
		

Crossrefs

Cf. A046899.

Programs

  • Mathematica
    LinearRecurrence[{4,-6,4,-1},{1,5,19,63},37] (* or *) Rest[CoefficientList[Series[x*(1+x+5*x^2+13*x^3)/(1-x)^4,{x,0,37}],x]] (* or *) a[n_]:=(-39 + 77*n - 45*n^2 + 10*n^3)/3;Array[a,37] (* James C. McMahon, Aug 17 2025 *)

Formula

Binomial transform of [1, 4, 10, 20, 0, 0, 0, ...], where (1, 4, 10, 20) = row 3 of triangle A046899
a(n) = (-39 + 77*n - 45*n^2 + 10*n^3)/3. - T. D. Noe, Aug 22 2008
G.f.: x*(1+x+5*x^2+13*x^3)/(1-x)^4. - Colin Barker, Mar 23 2012

Extensions

More terms from T. D. Noe, Aug 22 2008