OFFSET
0,1
COMMENTS
For real part of H(1/2 + i*sqrt(3)/2) see A339801.
FORMULA
Equals (Pi/2)*tanh(Pi*sqrt(3)/2) - sqrt(3)/2.
Equals Im(Psi(3/2 + i*sqrt(3)/2).
Equals -sqrt(3)/2 + Im(Psi(1/2 + i*sqrt(3)/2).
Equals Im((1 + i*sqrt(3))*Sum_{k>=0} 1/((1 + k)*(3 + i*sqrt(3) + 2*k))).
EXAMPLE
0.691215820928755403365848...
MATHEMATICA
RealDigits[N[Im[HarmonicNumber[1/2 + I Sqrt[3]/2]], 105]][[1]]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Artur Jasinski, Dec 17 2020
STATUS
approved