For each integer $n$, let $f(n)$ be the sum of the elements of the $n$th row (i.e. the row with $n+1$ elements) of Pascal's triangle minus the sum of all the elements from previous rows. For example, . [f(2) = (1+2+1) - (1+1+1) = 1] . What is the minimum value of $f(n)$ for$ n ≥ 2015?
