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A243596
Decimal expansion of the solid angle in steradians (sr) subtended by a cone with the polar angle of 1 radian (rad).
3
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
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
KEYWORD
nonn,cons,easy
AUTHOR
Stanislav Sykora, Jun 07 2014
STATUS
approved