<image>In his work "Detailed Explanation of the Nine Chapters on the Mathematical Art," the mathematician Yang Hui from the Song Dynasty of China introduced the "Yang Hui's Triangle" (see image). This diagram reveals the number of terms and the coefficients of each term in the expansion of \((a + b)^n\) (where \(n\) is a non-negative integer). 

For example:
\((a+b)^0 = 1\), it has only one term, and the coefficient is \(1\);
\((a+b)^1 = a + b\), it has two terms, and the coefficients are \(1\) and \(1\), with a sum of \(2\);
\((a+b)^2 = a^2 + 2ab + b^2\), it has three terms, and the coefficients are \(1\), \(2\), and \(1\), with a sum of \(4\);
\((a+b)^3 = a^3 + 3a^2b + 3ab^2 + b^3\), it has four terms, and the coefficients are \(1\), \(3\), \(3\), and \(1\), with a sum of \(8\), and so on.

Based on the above patterns, solve the problem: The sum of the coefficients of all terms in the expansion of \((a + b)^n\) is _____________.