On "Lost," there's a sequence of numbers that must be avoided at all costs: 4, 8, 15, 16, 23 and 42. But those numbers weren't the most important digits when it came to Sunday night's series finale — that all-important figure is closer to 13.5 million, the number of viewers who tuned in to the episode, appropriately titled "The End."

The pre-finale clip show, "Lost: The Final Journey," garnered 9.8 million viewers, while the post-show edition of "Jimmy Kimmel Live!," featuring interviews with castmembers and comedic alternate endings, attracted 3.4 million viewers.

Although the 13.5 million fans who watched the finale made up a strong enough audience to propel "Lost" to its best-rated episode in two years and well past the season finale of NBC's "The Celebrity Apprentice," it still wasn't a fantastic result, given the numbers the series was used to at its peak. During the show's first season, "Lost" averaged nearly 16 million viewers and subsequently declined to 11 million during season five. The pilot episode of "Lost" yielded a massive 18.6 million viewers.

Additionally, the "Lost" finale fell short in comparison to other similarly hyped series finales including "M.A.S.H." (121.6 million), "Seinfeld" (76.3 million) and "Friends" (52.5 million), while barely edging out the finales for HBO's cable offerings "The Sopranos" (11.9 million) and "Sex and the City" (10.6 million).

Despite a relatively lackluster viewership, the series finale performed rather admirably, given that the show's audience dwindled so dramatically over the course of its run, a fact that has been blamed on an increasingly complicated continuity and tough-to-crack story line.

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