What’s the best action to use when you want to do something only once per theme setup?

I’m writing a theme which has it’s own set of database tables.
I’m wondering what is the best action for me to use when I want my install function to be invoked only once when the theme is activated for the first time?

I know there is a setup_theme action, but not sure if that’s the one I should use.

You should read this: Activation/Deactivation hook for wordpress theme