OFFSET
1,2
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 2.28 p. 188.
LINKS
Steven R. Finch, Errata and Addenda to Mathematical Constants. 2.28 p. 26.
FORMULA
c = sqrt(2*(1 - sin(theta)/theta)), where theta is the smallest positive zero of tan(t)-t (theta = A115365).
EXAMPLE
1.560277942041879702102077381568463756373995745949542538537...
MATHEMATICA
digits = 103; theta = t /. FindRoot[Tan[t] == t, {t, 4}, WorkingPrecision -> digits+5]; c = Sqrt[2*(1 - Sin[theta]/theta)]; RealDigits[c, 10, digits] // First
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, Aug 13 2014
STATUS
approved