A019702 Decimal expansion of 2*Pi/21.

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

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• cons

Comments

Pi/105 = 0.1 * 2*Pi/21 is the mean area of the triangles that can be formed by breaking a unit-length stick in 3 parts, by uniformly and independently choosing 2 points on it (taking only those cases in which the 3 parts can form a triangle) (Mathai, 1999). - Amiram Eldar, Jul 28 2020

Examples

			0.299199300341885070329775560312333608018778038035724...
		

References

• A. M. Mathai, An Introduction to Geometrical Probability: Distributional Aspects with Applications, CRC Press, 1999. See example 2.5.3, pp. 269-270.

Links

• Ivan Panchenko, Table of n, a(n) for n = 0..1000
• Index entries for transcendental numbers

Crossrefs

Equals twice A019688.

Cf. A000796.

Programs

Mathematica

RealDigits[2*Pi/21, 10, 100][[1]] (* Amiram Eldar, Jul 28 2020 *)

PARI

2*Pi/21 \\ Charles R Greathouse IV, Oct 01 2022