1 Chronicles 2:30 lists the sons of Nadab as Seled and Appaim, but notes that Seled died without having any children. This verse is part of a genealogy, showing the family line and indicating that Seled’s branch did not continue.
The book of 1 Chronicles was written to record the genealogies of Israel, especially the tribe of Judah. This verse is simply reporting the descendants of Nadab, a member of this tribe, and highlights that Seled’s line ended with him because he had no sons. The focus is on tracing which family lines continued and which ones did not, which was important for understanding inheritance and tribal identity in ancient Israel.