Sered
Sered is the firstborn of Zebulun and the eponymous head of the Seredite clan. He is named twice in scripture, once at the descent into Egypt and once in the wilderness census that lists the families that came out of him.
Son of Zebulun
When Jacob's household goes down to Egypt, the muster of names that travel with him includes Zebulun's sons: "And the sons of Zebulun: Sered, and Elon, and Jahleel" (Gen 46:14). Sered stands first in the trio, his brothers Elon and Jahleel following.
Head of the Seredite Clan
Generations later, the wilderness census of Numbers carries the same three names forward as clan-heads within the tribe of Zebulun: "The sons of Zebulun after their families: of Sered, the family of the Seredites; of Elon, the family of the Elonites; of Jahleel, the family of the Jahleelites" (Num 26:26). What enters Egypt as a personal name leaves the wilderness as a tribal subdivision — the Seredites — one of the three families that make up Zebulun in the order of march.