list backup of archivelog?

I'm trying to zero in on the best rman command to view the most recent archive log in a particular backupset.  I copy archivelog dir off to a remote site and I'm trying to audit my logic to verify that the files I have remotely are managed correctly by my homegrown scripts.  "list backup of archivelog all" does tell me what I want to know, but it's messy because of the different tags.   Really it's the cleanup of the remote site I'm trying to verify.

So, what I want to ask rman is, "what is the last archivelog in the oldest backupset?"  All logs older than that can be removed from my remote backup.