Do examples as in the title exist? It depends on how the term Riemann sum is understood. For the standard, left, or right Riemann sums such examples do not exist. However, as we will see, they do ...

We characterize the nonreal zeros of the Riemann zeta function and their multiplicities, using the "asymptotic convergence degree" of "improper Riemann sums" for elementary improper integrals. The ...