\[\boxed{\mathbf{352}.}\]
\[(x + a)^{n} = C_{n}^{0} \cdot x^{n} +\]
\[+ C_{n}^{1} \cdot x^{n - 1}a + \ldots +\]
\[+ C^{n - 1} \cdot x \cdot a^{n - 1} + C_{n}^{n} \cdot a^{n}.\]
\[Если\ \ x = a = 1:\]
\[2^{n} = C_{n}^{0} + C_{n}^{1} + C_{n}^{2} + \ldots +\]
\[+ C_{n}^{n - 1} + c_{N}^{n}.\]
\[Что\ и\ требовалось\ доказать.\]