Chapter 1.5, Problem 1P

Use the preliminary test to decide whether the following series are divergent or require further testing. Careful: Do not say that a series is convergent; the preliminary test cannot decide this.

$\frac{1}{2}-\frac{4}{5}+\frac{9}{10}-\frac{16}{17}+\frac{25}{26}-\frac{36}{37}+\mathrm{...}$