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.

Showing 1-2 of 2 results.

A385647 Decimal expansion of 1 - log(2)/2.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Jul 06 2025

Keywords

Comments

Probability that floor(x/y) is even for x, y chosen randomly in (0,1).

Examples

			0.65342640972002734529138393927091171596224993281987...
		

Crossrefs

Essentially the same as A382854.

Programs

  • Magma
    SetDefaultRealField(RealField(100)); [1 - Log(2)/2]; // Vincenzo Librandi, Jul 07 2025
  • Mathematica
    First[RealDigits[1 - Log[2]/2, 10, 100]]

Formula

Equals 1 - A002162/2.

A210958 Decimal expansion of 1 - (Pi/4).

Original entry on oeis.org

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

Views

Author

Omar E. Pol, Aug 02 2012

Keywords

Comments

Decimal expansion of (4 - Pi)/4.
Area between a square and the inscribed quarter circle of radius 1.
Also area between a circle of radius 1 and the circumscribed square, divided by 4.
Also area between a circle of diameter 1 and the circumscribed square. - Omar E. Pol, Sep 24 2013
Also volume between a cube of side length 1 and the inscribed cylinder. - Omar E. Pol, Sep 25 2013

Examples

			0.21460183660255169038433915418012427895070765015622...
		

Crossrefs

Essentially the same as A091651.

Programs

Formula

1 - (Pi/4) = (4 - Pi)/4 = 1 - A003881 = A153799/4.
From Amiram Eldar, Jun 29 2020: (Start)
Equals Sum_{k>=0} (-1)^k/(2*k+3).
Equals Integral_{x=0..Pi/4} tan(x)^2 dx.
Equals Integral_{x=0..1} arcsin(x) dx /(1+x)^2.
Equals Integral_{x=1..oo} dx/(x^2+x^4). (End)
Equals -Integral_{x=0..1, y=0..1} arcsin(x*y)/((1+x*y)^2*log(x*y)) dx dy. (Apply Theorem 1 or Theorem 2 from Glasser (2019) to one of Amiram Eldar's integrals.) - Petros Hadjicostas, Jun 29 2020
Continued fraction 1/(3 + 3^2/(2 + 5^2/(2 + 7^2/(2 + ... )))). - Peter Bala, Feb 28 2024

Extensions

More terms from David Scambler, Aug 02 2012
Showing 1-2 of 2 results.