Solved Given the 15 puzzle
File:15-puzzle-loyd-bis.svg - Wikimedia Commons
File:15-puzzle.svg - Wikipedia
Wikipedia turns 15 years old today - Neowin
File:Wikipedia logo puzzle globe spins horizontally and vertically, revealing the contents of all of its puzzle pieces (4K resolution) (VP9).webm - Wikimedia Commons
15 Puzzle - Wikipedia
GitHub - GRpro/15puzzle_game: Console 15 puzzle game scala implementation.
Wikipedia at 15: all grown up - TechCentral
15 Puzzle - TV Tropes