natural numbers that occur in various counting problems, often involving recursively defined objects. They are named after the French-Belgian mathematician Eugène Charles Catalan.randomThe Feelings Roomretrieved2024-02-13subjectCatalon numbertagsSequence (Wikipedia)Natural number (Wikipedia)Wikipediawebsitehttps://en.wikipedia.org/wiki/Catalan_numberwikipedia ofCatalan number