Francis Villatoro on Twitter: "RT @octonion: I knew the 15 puzzle may take up to 80 single-moves to solve, but didn't know it's only 43 moves if you allow sliding multipl…" / Twitter
How to check if an instance of 15 puzzle is solvable? - GeeksforGeeks
N-Puzzle
Stack 'N Puzzles - A Puzzling Adventure for Kids! - 77SPARX
N-Puzzle (dynamic size and solver) - File Exchange - MATLAB Central
Alphabet N - Alphabet Jigzaw Puzzles for Kids | Mocomi