Izv. Vyssh. Uchebn. Zaved. Mat., 1986 Number 4,Pages 75–77(Mi ivm7542)
Brief communications
Expansion of the sums $\sum\limits_{n=1}^\infty n^{-\alpha}\cos 2\pi n\theta$ and $\sum\limits_{n=1}^\infty n^{-\alpha}\sin 2\pi n\theta$ in powers of $\theta$