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.
LINKS
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
KEYWORD
AUTHOR
Wolfdieter Lang, May 31 2015
STATUS
approved