Chapter 4 - Integration - 4.4 The Definition Of Area As A Limit; Sigma Notation - Exercises Set 4.4 - Page 297: 10

\begin{align} \sum_{k=1}^{50} (2k-1) = 1 +3+5+... + 97+99 \end{align}

We can represent the odd integers as 2k-1. Thus, the sum of the odd integers from 1 to 99 can be represented in sigma notation as: \begin{align} \sum_{k=1}^{50} (2k-1) = 1 +3+5+... + 97+99 \end{align}