Number of ways to build an expression using non-redundant parentheses in an expression of n variables, counted in decreasing sub-partitions of equal size.

A245390

Number of ways to build an expression using non-redundant parentheses in an expression of n variables, counted in decreasing sub-partitions of equal size.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =11a(4) =39a(5) =145a(6) =514a(7) =1901a(8) =6741a(9) =24880a(10) =87791a(11) =325634a(12) =1152725a(13) =4251234a(14) =15052387a(15) =55750323a(16) =197031808a(17) =729360141a(18) =2579285955a(19) =9539017676a(20) =33822222227a(21) =124889799518a(22) =440743675148

External references