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.

A263490 Decimal expansion of the generalized hypergeometric function 3F2(1/2,1/2,1/2 ; 1,1; x) at x=1/4.

Original entry on oeis.org

1, 0, 3, 5, 1, 2, 0, 6, 6, 1, 4, 2, 5, 6, 4, 8, 9, 8, 1, 0, 4, 5, 9, 5, 7, 5, 5, 1, 4, 5, 0, 8, 6, 2, 8, 4, 9, 9, 7, 4, 9, 4, 8, 7, 3, 2, 4, 4, 9, 8, 5, 9, 5, 7, 0, 6, 9, 1, 6, 1, 7, 7, 5, 7, 7, 1, 3, 6, 2, 0, 0, 0, 7, 7, 7, 0, 2, 3, 5, 5, 4, 2, 9, 4, 7, 5, 0, 2, 0, 5, 4, 0, 1, 3, 0, 3, 7, 6, 8, 9, 9
Offset: 1

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Author

R. J. Mathar, Oct 19 2015

Keywords

Comments

Multiplication with Pi^2/4 gives 2.554057.. = integral_{x=0..infinity} I_0(x) *K_0(x)^2 dx, where I and K are Modified Bessel Functions.

Examples

			1.0351206614256489810459575514...
		

Programs

  • Maple
    evalf(4*EllipticK(sqrt(2-sqrt(3))/2)^2 / Pi^2, 120); # Vaclav Kotesovec, Apr 10 2016
  • Mathematica
    RealDigits[HypergeometricPFQ[{1/2, 1/2, 1/2}, {1, 1}, 1/4], 10, 120][[1]] (* Vaclav Kotesovec, Apr 10 2016 *)
    RealDigits[4*EllipticK[(2 - Sqrt[3])/4]^2 / Pi^2, 10, 120][[1]] (* Vaclav Kotesovec, Apr 10 2016 *)
  • PARI
    4*ellK(sqrt(2-sqrt(3))/2)^2/Pi^2 \\ Charles R Greathouse IV, Feb 04 2025

Formula

Square of A243308.
From Vaclav Kotesovec, Apr 10 2016: (Start)
Equals 3^(1/2) * Gamma(1/3)^6 / (2^(8/3) * Pi^4).
Equals Gamma(1/6)^3 / (3 * 2^(5/3) * Pi^(5/2)).
(End)