A131594 Decimal expansion of sqrt(2)/3, the volume of a regular octahedron with edge length 1.

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

Offset: 0

Author

Omar E. Pol, Aug 30 2007

Keywords

• cons
• easy
• nonn

Comments

Volume of a regular octahedron: V = ((sqrt(2))/3)* a^3, where 'a' is the edge.

Examples

			0.471404520791031682933896...
		

References

• Jan Gullberg, Mathematics from the Birth of Numbers, W. W. Norton & Co., NY & London, 1997, §12.4 Theorems and Formulas (Solid Geometry), p. 450.

Links

• Ivan Panchenko, Table of n, a(n) for n = 0..1000
• Wikipedia, Platonic solid.
• Index entries for algebraic numbers, degree 2.

Crossrefs

Cf. A020829 (regular tetrahedron volume), A102208 (regular icosahedron volume), A102769 (regular dodecahedron volume).

Cf. A179587.

Programs

Mathematica

RealDigits[Sqrt[2]/3,10,120][[1]] (* Harvey P. Dale, May 27 2012 *)

PARI

sqrt(2)/3 \\ G. C. Greubel, Jul 06 2017

Formula

Equals A002193/3 = A010464/A010482. - R. J. Mathar, Dec 11 2009

Extensions

More digits from R. J. Mathar, Dec 11 2009