Bob and his strict mom

Bob's mom is strict. She wants Bob to study for the upcoming university entrance exam. Bob has only $N$ days left to study. So she asks Bob to make a schedule. Bob being the obedient son he is, comes up with a schedule quickly. But his mother isn't satisfied with the schedule. According to her, at the end of the $i^{th}$ day $(1 \leq i \leq N)$, the number of days on which Bob has studied till n