A273621 Decimal expansion of the solid angle (in steradians) subtended by a cone having the 'magic' angle A195696 as its polar angle.

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

Offset: 1

Author

Stanislav Sykora, Aug 15 2016

Keywords

• nonn
• cons

Comments

An example of such a cone is the one circumscribed to a cube from one of its vertices. When expressed as a fraction of the full solid angle, this constant leads to A156309.

Examples

			2.65558657871115077573713025127469430382620630256473049081011931...
		

Links

• Stanislav Sykora, Table of n, a(n) for n = 1..2000

Crossrefs

Cf. A000796, A156309, A195696, A210974.

Programs

Mathematica

First@RealDigits@N[2*Pi*(1 - Sqrt[1/3]), 25] (* G. C. Greubel, Aug 15 2016 *)

PARI

2*Pi*(1-sqrt(1/3))

Formula

Equals 2*Pi*(1-sqrt(1/3)) = 4*Pi*A156309 = 2*Pi*(1-cos(A210974)).