Lil Wayne Back Onstage in L.A. ... Days After Seizure Scares

Lil Wayne's a lil workhorse ... working again 2 days after suffering TWO scary seizures.

The rapper's currently at the gaming convention E3 in downtown L.A. promoting his new mobile app skating game. He stayed true to his word it'd be business as usual ... despite his private plane making two emergency landings in Omaha, Nebraska.

Noticeably absent from Weezy's hand ... a cup of lean. But look closely ... a friend appears to be double cupping.

We're no doctors ... but being near a double cup probably not the best idea.