Interestingly, there are three people who have co-authored 50 or more papers with Erdos. The most prolific is not a graph theorist, the next is also not though

Interestingly, there are three people who have co-authored 50 or more papers with Erdos. The most prolific is not a graph theorist, the next is also not thought of as a graph theorist. The third is listed as having published exactly 50 papers with Erdos, and is a graph theorist. More, there is a female math professor with the same surname, also in combinatorics and graph theory. Now I can guess where you did your university work. Fun game to play ...