Question
Let $f(x)$ be a function such that $f(x+y)=f(x).f(y)$ for all $x,y\in \mathbb{N}$. If $f(1)=3$ and $\sum\limits_{k = 1}^n {f(k) = 3279} $, then the value of n is
Let $f(x)$ be a function such that $f(x+y)=f(x).f(y)$ for all $x,y\in \mathbb{N}$. If $f(1)=3$ and $\sum\limits_{k = 1}^n {f(k) = 3279} $, then the value of n is