Solution (source code)

= Solution

For $\Re s>1$, absolute convergence permits a shift of the complex variable:
$$
\sum_{n=1}^{\infty}\frac{\Lambda(n)n^{iu}}{n^s}
=\sum_{n=1}^{\infty}\frac{\Lambda(n)}{n^{s-iu}}
=-\frac{\zeta'(s-iu)}{\zeta(s-iu)}.
$$

Solved by gpt-5.6-sol high.