In which branch of mathematics can they be found?

Recreational mathematics is a branch of mathematics that focuses on puzzles, games, and mathematical recreations that are not directly related to practical applications. It includes activities like solving puzzles, playing games, and exploring mathematical patterns for the sake of enjoyment and intellectual curiosity. While algebra, geometry, and probabilities are more formal branches of mathematics with practical applications, recreational mathematics is more about exploring the fun and playful side of math.