אָדָ֥ם שֵׁ֖ת אֱנֽוֹשׁ׃
ADAM, SETH, Enosh;
Rashi
And the sons of Carmi: Achar Now why do I call him Achar? Was his name not Achan? (It is explained) that [he was called thus] since he troubled Israel by transgressing the devoted thing, and because of him thirty-six thousand (sic) men fell. This is what I explained that whatever derogatory information he can tell, he tells, (but nevertheless) the kingship emanated from them.
Rabbeinu Bahya
This is also how Rav Saadyah Gaon explains our verse. He understood the words חלבו האליה as equivalent to חלבו והאליה, “its fat plus its tail.” We find that when enumerating the descendants of man the Book of Chronicles I 1,1 writes: אדם, שת אנוש when clearly the meaning is אדם, שת ואנוש “Adam, Sheth, and Enosh.” The same is true when the Torah enumerates constituent parts of the Tabernacle, writing: קרסיו, קרשיו, בריחיו, ועמודיו ואדוניו (Exodus 39,33). Although the connecting letter ו is omitted a couple of times, the verse is to be read as if the Torah had written it. The same is true of Leviticus 7,37 where the Torah writes לעולה למנחה. Clearly, the Torah did not mean to tell us that the burnt-offering is identical with the meal-offering, but the meaning is: “the burnt-offering as well as the meal-offering.” By the same token no one in his right mind would assume that Ezra (author of Chronicles) would have believed that Adam, Sheth, and Enosh were identical just because the connecting letter ו is absent in the text.
Ibn Ezra
קוץ שמיר Thorns, briers. Asyndeton. Comp. אדם שת אנוש (1 Chr. 1:1).