A258147 Decimal expansion of (4 - 3*sqrt(3)/Pi)/6: ratio of the area of a circular segment with central angle 2*Pi/3 and the area of the corresponding circular half-disk.

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

Offset: 0

Author

Wolfdieter Lang, May 31 2015

Keywords

• nonn
• cons
• easy

Comments

See the comments on A258146.

This is also the ratio of the area of a circular disk (radius R) without an inscribed central rectangle (2*x = R, 2*y = sqrt(3)*R) together with the two opposing circular segments each with central angle Pi/3 and the area Pi*R^2 of the circular disk.

Links

• G. C. Greubel, Table of n, a(n) for n = 0..5000
• Index entries for transcendental numbers

Crossrefs

Cf. A258146, A258148.

Programs

Mathematica

RealDigits[2/3 - Sqrt[3]/(2*Pi), 10, 50][[1]] (* G. C. Greubel, Oct 19 2017 *)

PARI

2/3 - sqrt(3)/(2*Pi) \\ Michel Marcus, Oct 19 2017

Formula

2/3 - sqrt(3)/(2*Pi) = 0.39100221895577064191100...