A   6200 or 9745   or 2245

A5 (power chord) 2200

A7   6500   or 6540 or 2540

Am   5200 or 2235

Lots of possibilities going up and down the neck. All are reacheable with a bit of practice. That's the nice thing about a mandolin. Learn the scales, where the notes are and what notes make up what chords. Then experiment and come up with your own arrangements for improvisation.