1. The problem is to find the sum of the first 19 terms of an arithmetic sequence. 2. The sum of the first $n$ terms of an arithmetic sequence is given by the formula $$S_n = \frac{n}{2} (2a + (n-1)d)$$ where $n$ is the number of terms, $a$ is the first term, and $d$ is the common difference. 3. However, the problem has not provided the values of the first term $a$ or the common difference $d$. 4. Without the values of $a$ and $d$, we cannot calculate a numerical answer. 5. If you provide the first term and common difference, I can calculate the sum for you.