The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A019702 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A019702

Decimal expansion of 2*Pi/21.
(history; published version)

#15 by Charles R Greathouse IV at Sat Oct 01 00:27:16 EDT 2022

STATUS

editing

approved

#14 by Charles R Greathouse IV at Sat Oct 01 00:27:12 EDT 2022

LINKS

<a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>

PROG

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

STATUS

approved

editing

#13 by Peter Luschny at Tue Jul 28 11:12:05 EDT 2020

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reviewed

approved

#12 by Joerg Arndt at Tue Jul 28 10:31:18 EDT 2020

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proposed

reviewed

#11 by Amiram Eldar at Tue Jul 28 03:46:00 EDT 2020

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editing

proposed

#10 by Amiram Eldar at Tue Jul 28 03:12:45 EDT 2020

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

REFERENCES

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

EXAMPLE

0.299199300341885070329775560312333608018778038035724...

MATHEMATICA

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

CROSSREFS

Cf. A000796.

STATUS

approved

editing

#9 by Joerg Arndt at Sun Aug 31 05:13:30 EDT 2014

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proposed

approved

#8 by Michel Marcus at Sun Aug 31 04:24:02 EDT 2014

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editing

proposed

#7 by Michel Marcus at Sun Aug 31 04:23:59 EDT 2014

CROSSREFS

Equals twice A019688.

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proposed

editing

#6 by Ivan Panchenko at Sun Aug 31 04:14:12 EDT 2014

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editing

proposed