chihik

摘要： \[ f(n)=\sum_{i=0}^n \binom{n}{i} p^i\lfloor \frac{i}{k} \rfloor $$ \] \begin{aligned} f(n+1)&=p^{n+1}\lfloor \frac{n+1}{k} \rfloor+ \sum_{i=0}n (\bin 阅读全文