Catalan number
A kind of number
About Catalan number
Catalan numbers C_n = (2n choose n)/(n+1) count many combinatorial structures: binary trees, Dyck paths, non-crossing partitions, etc. The first few are 1, 2, 5, 14, 42, 132, 429.
Key features
- Named after Eugène Charles Catalan.
- C_0 = 1, C_1 = 1, C_2 = 2, C_3 = 5, C_4 = 14, C_5 = 42, ….
Examples:
1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796