A019696 Decimal expansion of 2*Pi/9.

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

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• cons

Comments

The area of a deltoid formed by rolling a circle with radius 1/3 inside a unit-radius circle. - Amiram Eldar, Nov 16 2021

Volume shared by a sphere of radius 1 inscribed in a cube and one of the six pyramids inscribed in the cube. - Omar E. Pol, Sep 01 2024

Examples

			0.69813170079773183076947630739544508537714875541669...
		

Links

• Ivan Panchenko, Table of n, a(n) for n = 0..1000
• Eric Weisstein's World of Mathematics, Deltoid.
• Index entries for transcendental numbers

Crossrefs

Equals twice A019676.

Programs

Mathematica

RealDigits[(2*Pi)/9,10,120][[1]] (* Harvey P. Dale, Aug 24 2013 *)

PARI

2*Pi/9 \\ Michel Marcus, Nov 16 2021