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.

A145960 Decimal expansion of 2*log(5/3) used in BBP Pi formula.

Original entry on oeis.org

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

Views

Author

Artur Jasinski, Oct 25 2008

Keywords

Comments

BBP formula for Pi = 4*A145963 - (1/2)*A145960 - (1/2)*(A145961-A145962).

Examples

			1.021651247531981366411...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[2 Log[5/3], 10, 100]]
  • PARI
    2*log(5/3) \\ Michel Marcus, Apr 05 2015

Formula

Equals 2*log(5/3) = 2*(log(5)-log(3)) = 2*(A016628 - A002391) = log(25/9) = 4*arctanh(1/4).
Equals Hypergeometric2F1(1, 1/2, 3/2, 1/16).
Equals Sum_{k>=0} (1/16)^k*(1/(2k+1)).