Genesis 46:8
And these are the names of the children of Israel, which came into Egypt, Jacob and his sons: Reuben, Jacob’s firstborn. And these are the names of the children of Israel, which came into Egypt, Jacob and his sons: Reuben, Jacob’s firstborn.
The names listed are those of the children of Israel who entered Egypt, namely Jacob himself together with his sons. At the head of that family record stands Reuben, expressly distinguished as Jacob's firstborn. This listing belongs to the larger movement in which Jacob's entire household went down to Egypt to settle there. That family migration followed the earlier, separate journey when his sons had gone to Egypt to purchase grain because of the famine.