Who was Alan in Treasure Island?

In "Treasure Island," Alan is not a major character, and there is no prominent figure by that name in Robert Louis Stevenson's novel. The story primarily revolves around Jim Hawkins, Long John Silver, and other key characters like Squire Trelawney and Dr. Livesey. If you meant a different character or context related to "Treasure Island," please provide more details for clarification.