Genesis 4:16-18

So Cain went away from the LORD and lived in the land of Nod, east of Eden. He had sexual relations with his wife, and she became pregnant and gave birth to Enoch. At that time Cain was building a city, which he named after his son Enoch. Enoch had a son named Irad, Irad had a son named Mehujael, Mehujael had a son named Methushael, and Methushael had a son named Lamech.