Rteyu had a son named Rantinava, who had three sons, named Sumati, Dhruva and Apratiratha. Apratiratha had only one son, whose name was Kanva

Expressions researched:
"Ṛteyu had a son named Rantināva, who had three sons, named Sumati, Dhruva and Apratiratha. Apratiratha had only one son, whose name was Kaṇva"

Srimad-Bhagavatam

SB Canto 9

Ṛteyu had a son named Rantināva, who had three sons, named Sumati, Dhruva and Apratiratha. Apratiratha had only one son, whose name was Kaṇva.

SB 9.20.6, Translation

Ṛteyu had a son named Rantināva, who had three sons, named Sumati, Dhruva and Apratiratha. Apratiratha had only one son, whose name was Kaṇva.