[ust]

Yes, there is oathtool that you can use on Linux (well, that's how it's called in Debian). I use the same, just type:

oathtool --totp -b "key value"

where your "key value" is your secret (same thing you would get if you scan QR code). And then you just need to keep the secret safe, and you can run it on as many devices you need.

EDIT: just realized that michaelt had much more substantial comment.