Numbers 26:1-2, 19-22

After the plague GOD said to Moses and Eleazar son of Aaron the priest, “Number the entire community of Israel by families—count every person who is twenty years and older who is able to serve in the army of Israel.”

Er and Onan were sons of Judah who died early on in Canaan. The sons of Judah by clans: Shelah and the Shelanite clan, Perez and the Perezite clan, Zerah and the Zerahite clan. The sons of Perez: Hezron and the Hezronite clan, Hamul and the Hamulite clan. These were the clans of Judah. They numbered 76,500.