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.

A160291 Numerator of Hermite(n, 1/30).

Original entry on oeis.org

1, 1, -449, -1349, 604801, 3033001, -1357769249, -9546871949, 4267426262401, 38636165278801, -17244440197445249, -191107183952049749, 85168871793401932801, 1117147665134470577401, -497120752326266836308449, -7535151042673431473934749, 3348029927159627713608096001
Offset: 0

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Author

N. J. A. Sloane, Nov 12 2009

Keywords

Examples

			Numerators of 1, 1/15, -449/225, -1349/3375, 604801/50625, ...
		

Crossrefs

Cf. A001024 (denominators).

Programs

  • Magma
    [Numerator((&+[(-1)^k*Factorial(n)*(1/15)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]])): n in [0..30]]; // G. C. Greubel, Oct 03 2018
  • Mathematica
    Table[15^n*HermiteH[n, 1/30], {n, 0, 30}] (* G. C. Greubel, Oct 03 2018 *)
  • PARI
    a(n)=numerator(polhermite(n, 1/30)) \\ Charles R Greathouse IV, Jan 29 2016
    
  • PARI
    x='x+O('x^30); Vec(serlaplace(exp(x - 225*x^2))) \\ G. C. Greubel, Oct 03 2018
    

Formula

From G. C. Greubel, Oct 03 2018: (Start)
a(n) = 15^n * Hermite(n, 1/30).
E.g.f.: exp(x - 225*x^2).
a(n) = numerator(Sum_{k=0..floor(n/2)} (-1)^k*n!*(1/15)^(n-2*k)/(k!*(n-2*k)!)). (End)