logcf: Continued Fraction Approximation of Log-Related Series
Description
Compute a continued fraction approximation to the series (infinite sum)
$$\sum_{k=0}^\infty \frac{x^k}{i +k\cdot d} = \frac{1}{i} + \frac{x}{i+d} +
\frac{x^2}{i+2*d} + \frac{x^3}{i+3*d} + \ldots$$