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

1,1

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.

Links

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

Formula

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

Example

2.65558657871115077573713025127469430382620630256473049081011931...

Mathematica

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

Prog

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

Crossrefs

Cf. A000796, A156309, A195696, A210974.

Sequence in context: A105029 A309040 A316134 * A190124 A067548 A354509

Adjacent sequences: A273618 A273619 A273620 * A273622 A273623 A273624

Keyword

nonn,cons

Author

Stanislav Sykora, Aug 15 2016

Status

approved