OFFSET
1,1
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge, 2003, Section 8.9 Hyperbolic Volume Constants p. 512.
LINKS
Eric Weisstein's MathWorld, Gieseking's Constant
Eric Weisstein's MathWorld, Polygamma Function
FORMULA
5*(9 - Polygamma(1, 2/3) + Polygamma(1, 4/3)) / (4*sqrt(3)).
EXAMPLE
5.0747080320482681251060127713726...
MATHEMATICA
G = (9 - PolyGamma[1, 2/3] + PolyGamma[1, 4/3])/(4*Sqrt[3]); RealDigits[5*G, 10, 104] // First
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, Jun 26 2014
STATUS
approved