Number of asymmetric Dyck paths of semilength n.

Terms

a(0) =0a(1) =0a(2) =2a(3) =8a(4) =32a(5) =112a(6) =394a(7) =1360a(8) =4736a(9) =16544a(10) =58324a(11) =207088a(12) =741184a(13) =2671008a(14) =9688410a(15) =35344800a(16) =129620480a(17) =477590080a(18) =1767170812a(19) =6563935664a(20) =24465914304a(21) =91481858208a(22) =343058261572