Number of 2n-length strings of balanced parentheses of exactly 3 different types that are introduced in ascending order.
A258391
Number of 2n-length strings of balanced parentheses of exactly 3 different types that are introduced in ascending order.
Terms
- a(0) =5a(1) =84a(2) =1050a(3) =11880a(4) =129129a(5) =1381380a(6) =14707550a(7) =156706680a(8) =1675459786a(9) =17998446312a(10) =194361212500
External references
- oeis: A258391