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.

A120248 a(n) = Product_{k=0..n} C(n+k+2, n+2).

Original entry on oeis.org

1, 4, 75, 7056, 3457440, 9032601600, 127843321480875, 9917120529316000000, 4253520573615071657074176, 10156681309872614660803421798400, 135766978921156343322148046967386880000, 10205737152660536205131284348877857357824000000
Offset: 0

Views

Author

Paul Barry, Jun 12 2006

Keywords

Comments

Divisors in number triangle A120247.

Crossrefs

Cf. A120247.

Programs

  • Magma
    A120248:= func< n | (&*[Binomial(n+j+2, n+2): j in [0..n]]) >;
    [A120248(n): n in [0..20]]; // G. C. Greubel, Mar 16 2023
    
  • Mathematica
    Table[Gamma[n+2]*BarnesG[2*n+4]/((Gamma[n+3])^(n-1)*BarnesG[n+4]^2), {n,0,20}] (* G. C. Greubel, Mar 16 2023 *)
  • PARI
    a(n) = prod(k=0, n, binomial(n+k+2, n+2)); \\ Michel Marcus, Mar 16 2023
  • SageMath
    def A120248(n): return product( binomial(n+j+2, n+2) for j in range(n+1))
    [A120248(n) for n in range(21)] # G. C. Greubel, Mar 16 2023
    

Formula

a(n) = Gamma(n+2)*BarnesG(2*n+4)/((Gamma(n+3))^(n-1)*BarnesG(n+4)^2). - G. C. Greubel, Mar 16 2023
a(n) ~ A * 2^(47/12 + 11*n/2 + 2*n^2) / (exp(19/6 + 2*n + n^2/2) * Pi^((n+1)/2) * n^(5/12 + n/2)), where A = A074962 is the Glaisher-Kinkelin constant. - Vaclav Kotesovec, Aug 29 2023