A120671 Decimal expansion of arccos(1-8/(Pi^2)) / (2*Pi).

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

Offset

0,1

Comments

The average arc length between two randomly chosen points on a circle of radius r is r*A120669 corresponding to the average chord length r*A088538. (Each arc averaged is no larger than the semicircle.). This sequence is the ratio of that average arc length to the circumference (and is thus also the ratio of the corresponding sector's area to the circle's area).

Links

Table of n, a(n) for n=0..104.

Formula

Equals A120669/(2*Pi) = A120670/360.

Example

0.219667909710056641181661197550...

Mathematica

RealDigits[ArcCos[(1-(8/(Pi^2) ))]/(2Pi), 10, 120][[1]] (* Harvey P. Dale, Jun 17 2018 *)

Prog

(PARI) acos(1-8/Pi^2)/(2*Pi)

Crossrefs

Cf. A088538, A120669 (2*Pi*A120671), A120670 (360*A120671).

Sequence in context: A141028 A246323 A201685 * A245461 A086572 A349035

Adjacent sequences: A120668 A120669 A120670 * A120672 A120673 A120674

Keyword

cons,nonn

Author

Rick L. Shepherd, Jun 22 2006

Status

approved