\Bigg \{{n \choose 0}\cdot{n \choose n}+{n \choose 1}\cdot{n \choose n-1}+{n \choose 2}\cdot{n \choose n-2}+{n \choose 3}\cdot{n \choose n-3}+...+{n \choose n-1}\cdot{n \choose 1}+{n \choose n}\cdot{n \choose 0}\Bigg \}\cdot {x^n}