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A258147
Decimal expansion of (4 - 3*sqrt(3)/Pi)/6: ratio of the area of a circular segment with central angle 2*Pi/3 and the area of the corresponding circular half-disk.
4
3, 9, 1, 0, 0, 2, 2, 1, 8, 9, 5, 5, 7, 7, 0, 6, 4, 1, 9, 1, 1, 0, 0, 3, 4, 1, 7, 5, 1, 0, 1, 8, 1, 9, 4, 5, 9, 6, 7, 9, 7, 3, 4, 2, 6, 4, 8, 3, 3, 4, 6, 3, 4, 0, 2, 6, 6, 9, 8, 3, 6, 5, 6, 5, 2, 1, 1, 5, 1, 5, 1, 4, 9, 3, 2, 0, 3, 1, 7, 6, 9
OFFSET
0,1
COMMENTS
See the comments on A258146.
This is also the ratio of the area of a circular disk (radius R) without an inscribed central rectangle (2*x = R, 2*y = sqrt(3)*R) together with the two opposing circular segments each with central angle Pi/3 and the area Pi*R^2 of the circular disk.
FORMULA
2/3 - sqrt(3)/(2*Pi) = 0.39100221895577064191100...
MATHEMATICA
RealDigits[2/3 - Sqrt[3]/(2*Pi), 10, 50][[1]] (* G. C. Greubel, Oct 19 2017 *)
PROG
(PARI) 2/3 - sqrt(3)/(2*Pi) \\ Michel Marcus, Oct 19 2017
CROSSREFS
Sequence in context: A206160 A112972 A334191 * A016673 A304022 A103556
KEYWORD
nonn,cons,easy
AUTHOR
Wolfdieter Lang, May 31 2015
STATUS
approved