Let ( ) 1 3 3 100 n fn n é ù = + ê ú ë û , where [n] denotes the greatest integer less than or equal to n. Then ( ) 56 n 1 f n = å is equal to

Let $f(n)=\left[\frac{1}{3}+\frac{3 n}{100}\right] n$, where $[\mathrm{n}]$ denotes the greatest integer less than or equal to $n$. Then $\sum_{n=1}^{56} f(n)$ is equal to: