On a restricted linear congruence

Khodakhast Bibak, Bruce M. Kapron, Venkatesh Srinivasan

Let $b,n\in \mathbb{Z}$, $n\ge 1$, and ${\mathcal{D}}_1,\dots ,{\mathcal{D}}_{\tau (n)}$ be all positive divisors of $n$. For $1\le l\le \tau (n)$, define ${\cal C}_l:=\lbrace 1 \leqslant x\le…