login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A165922 Decimal expansion of 2*sqrt(3)/(9*Pi). 5
1, 2, 2, 5, 1, 7, 5, 3, 2, 3, 1, 5, 9, 5, 3, 7, 8, 8, 7, 8, 0, 2, 9, 4, 7, 7, 7, 4, 0, 2, 8, 8, 2, 0, 9, 8, 0, 8, 8, 3, 0, 8, 1, 0, 6, 7, 4, 8, 1, 4, 2, 3, 6, 7, 2, 8, 8, 7, 4, 8, 0, 0, 4, 5, 0, 9, 1, 1, 7, 8, 4, 5, 2, 1, 5, 3, 9, 3, 2, 8, 7, 7, 4, 2, 3, 0, 6, 6, 7, 3, 0, 7, 1, 8, 1, 5, 7, 5, 3, 1, 5, 7, 2, 6, 6 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The ratio of the volume of a regular tetrahedron to the volume of the circumscribed sphere. (The MathWorld link shows that the circumradius for a tetrahedron with side length a is a*sqrt(6)/4.)

LINKS

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

Jackson, Frank and Weisstein, Eric W., "Tetrahedron"

FORMULA

2*sqrt(3)/(9*Pi) = A010469/(9*A000796) = (2/9)*A002194/A000796 = (2/9)*A002194*A049541 = 2*A020784/A000796 = 2*3^(-3/2)/Pi.

EXAMPLE

0.122517532315953788780294777402882098...

MATHEMATICA

RealDigits[(2Sqrt[3])/(9Pi), 10, 120][[1]] (* Harvey P. Dale, Nov 17 2013 *)

PROG

(PARI) 2*3^(-3/2)/Pi

CROSSREFS

Cf. A000796, A002194, A010469, A049541, A020784.

Sequence in context: A286150 A071950 A274847 * A307834 A326616 A249033

Adjacent sequences:  A165919 A165920 A165921 * A165923 A165924 A165925

KEYWORD

cons,nonn

AUTHOR

Rick L. Shepherd, Sep 30 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 18 18:56 EDT 2019. Contains 328197 sequences. (Running on oeis4.)