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.

A145439 Decimal expansion of Sum_{k>=0} binomial(4*k, 2*k)/2^(6*k).

Original entry on oeis.org

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

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Author

R. J. Mathar, Feb 08 2009

Keywords

Examples

			1.11535507165041054076705837455583093794582718446458...
		

References

  • Alexander Apelblat, Tables of Integrals and Series, Harri Deutsch, 1996, 4.1.49.

Crossrefs

Programs

  • Maple
    1/2*(1+1/3*3^(1/2))*2^(1/2);
  • Mathematica
    RealDigits[1/Sqrt[2] + 1/Sqrt[6], 10, 120][[1]] (* Amiram Eldar, May 29 2023 *)
  • PARI
    1/sqrt(6) + 1/sqrt(2) \\ Michel Marcus, Jan 15 2021

Formula

Equals (1+A020760)*A010503.
Equals A020763 + A010503. - Artur Jasinski, Dec 20 2020
The minimal polynomial is 9*x^4 - 12*x^2 + 1. - Joerg Arndt, Sep 20 2023
Equals 2F1(1/4,3/4; 1/2; 1/4). - R. J. Mathar, Aug 02 2024
Equals Product_{k>=1} (1 - (-1)^k/A092259(k)). - Amiram Eldar, Nov 24 2024

Extensions

Typo in definition corrected by R. J. Mathar, Feb 09 2009