C_n = (1/(n+1)) C(2n,n). Counts Dyck paths, binary trees, triangulations, non-crossing matchings. Generating function 1−√(1−4x))/(2x).
C_n = (1/(n+1)) C(2n,n). Counts Dyck paths, binary trees, triangulations, non-crossing matchings. Generating function 1−√(1−4x))/(2x).