As a famous example of the sliding puzzle, it can be proved that the 15 puzzle can be represented by the alternating group A 15 {\displaystyle A_{15}} ,2 because the combinations of the 15 puzzle can be generated by 3-cycles. In fact, any n × m {\displaystyle n\times m} sliding puzzle with square tiles of equal size can be represented by A n m − 1 {\displaystyle A_{nm-1}} .
Mike Keith. "Vintage plastic sliding-letter puzzles" (PDF). Archived from the original (PDF) on 2014-12-17. https://web.archive.org/web/20141217140643/http://www.cs.brandeis.edu/~storer/JimPuzzles/SLIDE/CornellCrossword/KeithArticle2011.pdf ↩
Beeler, Robert. "The Fifteen Puzzle: A Motivating Example for the Alternating Group" (PDF). faculty.etsu.edu/. East Tennessee State University. Archived from the original (PDF) on 2021-01-07. Retrieved 2020-12-26. https://web.archive.org/web/20210107214840/https://faculty.etsu.edu/beelerr/fifteen-supp.pdf ↩