Well, no, it's not really a 'recent' interview. But it's a good one, from the 70's. You can find many cool lectures searching for

"knuth christmas tree lecture"

on youtube. They're all about counting problems related to trees. My current favorite is still the one about "3/2 trees", but I didn't get very far watching them all, yet!

more #knuth #mathLecture's, on #counting #trees, #mathematics