8. Write the following series in sigma notation. \[ 2+9+16+23+30+37 \]

Step 1 ：Identify the series as an arithmetic series where each term is 7 more than the previous term.

Step 2 ：The first term is 2.

Step 3 ：Write this series in sigma notation as the sum from i=0 to n of the first term plus i times the common difference.

Step 4 ：In this case, the first term is 2 and the common difference is 7.

Step 5 ：The number of terms, n, is 6 because there are 6 terms in the series.

Step 6 ：Write the series in sigma notation as \(2 + \sum_{i=1}^{6} 7i\).

Step 7 ：\(\boxed{2 + \sum_{i=1}^{6} 7i}\) is the final answer.