A243596 Decimal expansion of the solid angle in steradians (sr) subtended by a cone with the polar angle of 1 radian (rad).

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

Offset

1,1

Comments

Given a right circular cone with polar angle theta, the solid angle it subtends is 2*Pi(1-cos(theta)). Not to be confused with the area, in steradians, of a spherical square with the side theta (see A231986).

Links

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

Wikipedia, Solid angle

Wikipedia, Steradian

Wikipedia, Cone

Formula

2*Pi*(1-cos(1)) = 4*Pi*A243597.

Example

2.8883657975136401375431217405500923198415259929590102...

Mathematica

RealDigits[2 Pi (1 - Cos[1]), 10, 111][[1]] (* Robert G. Wilson v, Jun 12 2014 *)

Prog

(PARI) 2*Pi*(1-cos(1))

Crossrefs

Cf. A231986, A243597 (fraction of full solid angle).

Sequence in context: A105388 A178247 A048651 * A256849 A138300 A137575

Adjacent sequences: A243593 A243594 A243595 * A243597 A243598 A243599

Keyword

nonn,cons,easy

Author

Stanislav Sykora, Jun 07 2014

Status

approved