Number of 2n-length strings of balanced parentheses of exactly 9 different types that are introduced in ascending order.

A258397

Number of 2n-length strings of balanced parentheses of exactly 9 different types that are introduced in ascending order.

Terms

    a(0) =4862a(1) =755820a(2) =67897830a(3) =4633467300a(4) =267074035800

External references