OFFSET
1,2
REFERENCES
S. R. Finch, Mathematical Constants, Cambridge, 2003, Section 3.10 p. 233.
LINKS
David W. Boyd, Sharp inequalities for the product of polynomials
Eric Weisstein's MathWorld, Clausen's Integral
FORMULA
exp(5/Pi*Clausen2(Pi - Pi/5)), where Clausen2 is Clausen's Integral.
EXAMPLE
1.967044901088071888351432414582828054693451...
MATHEMATICA
Clausen2[x_] := Im[PolyLog[2, Exp[x*I]]]; c[m_] := Exp[m/Pi*Clausen2[Pi - Pi/m]]; RealDigits[c[5], 10, 100] // First
PROG
(PARI) exp(5*imag(polylog(2, exp(4*I*Pi/5)))/Pi) \\ Charles R Greathouse IV, Jul 15 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, May 21 2014
STATUS
approved