OFFSET
0,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..10000
D. Borwein, J. M. Borwein, M. L. Glasser, J. G Wan, Moments of Ramanujan's Generalized Elliptic Integrals and Extensions of Catalan's Constant, 2010.
D. Borwein, J. M. Borwein, M. L. Glasser, J. G Wan, Moments of Ramanujan's Generalized Elliptic Integrals and Extensions of Catalan's Constant, Journal of Mathematical Analysis and Applications, Volume 384, Issue 2, 15 December 2011, Pages 478-496.
FORMULA
G(s) = (Pi/4) * 3F2(1/2, 1/2-s, s+1/2; 1, 3/2; 1), with 2F1 the hypergeometric function.
G(s) = (1/(8*s))*(Pi + cos(Pi*s)*(psi(1/4+s/2) - psi(3/4+s/2))), where psi is the digamma function (PolyGamma).
G(1/12) = 3*(sqrt(3)+1)*(log(sqrt(2)-1) + (sqrt(3)/2)*log(sqrt(3)+sqrt(2))).
EXAMPLE
0.91205508937271840001882865569309753445114291198031874684362426...
MATHEMATICA
RealDigits[3*(Sqrt[3]+1)*(Log[Sqrt[2]-1] + (Sqrt[3]/2)*Log[Sqrt[3]+ Sqrt[2]]), 10, 103] // First
N[Pi*HypergeometricPFQ[{5/12, 1/2, 7/12}, {1, 3/2}, 1]/4, 106] (* Vaclav Kotesovec, Apr 24 2015 *)
PROG
(PARI) 3*(sqrt(3)+1)*(log(sqrt(2)-1) + (sqrt(3)/2)*log(sqrt(3)+ sqrt(2))) \\ G. C. Greubel, Aug 24 2018
(Magma) SetDefaultRealField(RealField(100)); 3*(Sqrt(3)+1)*(Log(Sqrt(2)-1) + (Sqrt(3)/2)*Log(Sqrt(3)+ Sqrt(2))) // G. C. Greubel, Aug 24 2018
CROSSREFS
KEYWORD
AUTHOR
Jean-François Alcover, Apr 23 2015
STATUS
approved