The story
Named after the Belgian mathematician Eugène Catalan (1814–1894).
Etymology from Wiktionary, CC BY-SA 4.0.
Catalan number
Today it means: In combinatorial mathematics, any of a sequence of natural numbers that occur in various counting problems, often involving recursively defined objects; the nᵗʰ Catalan number is equal to (2n choose n) over (n+1). Full definition →