a(n) = Bell(n-1)*Motzkin(n).

Terms

a(0) =1a(1) =2a(2) =8a(3) =45a(4) =315a(5) =2652a(6) =25781a(7) =283271a(8) =3456900a(9) =46269636a(10) =672423050a(11) =10525299270a(12) =176275830495