Lambert series of logarithm, the derivative of Deninger’s function $R(z),$ and a mean value theorem for $\zeta \left (\frac {1}{2}-it\right )\zeta ‘\left (\frac {1}{2}+it\right )$

An explicit transformation for the series , or equivalently, for Re, which takes y to , is obtained for the first time. This series transforms into a series containing the derivative of , a function studied by Christopher Deninger while obtaining an a…