2.1. How many terms will there be if we expand the expression $\left(4 x^{3}+x^{-3}+2\right)^{2016}$ and combine like terms?
Answer: 4033.

Solution. In the resulting sum, there will be monomials of the form $k_{n} x^{3 n}$ for all integers $n \in[-2016 ; 2016]$ with positive coefficients $k_{n}$, i.e., a total of $2 \cdot 2016+1=4033$ terms.