# Math Help - divergence

1. ## divergence

prove that the series 1+1/4+1/7+1/10... diverges.

2. Originally Posted by alexandrabel90
prove that the series 1+1/4+1/7+1/10... diverges.
Have you written the the formula that produces this series?

$\frac{1}{1}+\frac{1}{4}+\frac{1}{7}+...=\sum_{n=1} ^{\infty}\frac{1}{3n-2}$

3. Originally Posted by dwsmith
Have you written the the formula that produces this series?

$\frac{1}{1}+\frac{1}{4}+\frac{1}{7}+...=\sum_{n=1} ^{\infty}\frac{1}{3n-2}$
I'll just add that it should now be clear that an appropriate test can be used.