In Shmuel 1, 17:12, the sons of Yishai are listed. There is a discrepancy between this count (of 7) and the textual statements that Yishai had 8 sons. Some meforshim explain this as because the 8th, Elihu, was only a half brother. Rashi explains, though,
And he had eight sons. And that which is stated, 'Otzem, the sixth, Dovid the seventh,'(Chron 1, 2:15) and no more is stated. This may be reconciled that one died childless and therefore, he was not mentioned there.
How does Rashi draw this conclusion? Would a person's dying childless justify his name's not being recorded? Are there other instances where someone who died without children is omitted from a Torah listing?