Euler's divergent series in arithmetic progressions

Anne-Maria Ernvall-Hytönen, Tapani Matala-aho, Louna Seppälä

Let $\xi$ and $m$ be integers satisfying $\xi \ne 0$ and $m\ge 3$. We show that for any given integers $a$ and $b$, $b\ne 0$, there are $\frac{\phi (m)}{2}$ reduced residue classes modulo…