# Thread: Does this series conv or div?? [tricky]

1. ## Does this series conv or div?? [tricky]

Determine whether summation div or conv.

Summation of [3^n * n!]/[1*4*(3n-2)]

2. Originally Posted by WartonMorton
Determine whether summation div or conv.

Summation of [3^n * n!]/[1*4*(3n-2)]

It's trivial to show that the general term sequence doesn't even converge to zero ...!

Tonio

3. Originally Posted by tonio
It's trivial to show that the general term sequence doesn't even converge to zero ...!

Tonio
not quite sure what you mean by this?

4. Originally Posted by WartonMorton
not quite sure what you mean by this?

It means that $\lim_{n\to\infty}a_n\neq 0\Longrightarrow \sum^\infty_{n=1}a_n$ doesn't converge. This is ABC in infinite series.

Tonio