a(n) = prime(n)*Catalan(n).

Terms

a(0) =2a(1) =6a(2) =25a(3) =98a(4) =462a(5) =1716a(6) =7293a(7) =27170a(8) =111826a(9) =487084a(10) =1822366a(11) =7696444a(12) =30458900a(13) =115000920a(14) =455657715a(15) =1873956510a(16) =7649042610a(17) =29135960700a(18) =118406633730a(19) =466052549820