Number of bipartite partitions.

Terms

a(0) =4a(1) =9a(2) =21a(3) =40a(4) =74a(5) =125a(6) =209a(7) =330a(8) =515a(9) =778a(10) =1160a(11) =1690a(12) =2439a(13) =3457a(14) =4857a(15) =6735a(16) =9264a(17) =12607a(18) =17040a(19) =22826a(20) =30391a(21) =40165a(22) =52788a(23) =68938a(24) =89589a(25) =115778a(26) =148957a(27) =190714a(28) =243184a(29) =308746