a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 0, 1, 2, 0.

Terms

a(0) =0a(1) =1a(2) =2a(3) =0a(4) =2a(5) =4a(6) =2a(7) =12a(8) =18a(9) =24a(10) =82a(11) =120a(12) =242a(13) =620a(14) =1010a(15) =2324a(16) =5154a(17) =9520a(18) =22178a(19) =46512a(20) =94178a(21) =214548a(22) =446690a(23) =952732a(24) =2122034a(25) =4475592a(26) =9776626a(27) =21491496a(28) =46096338a(29) =101585276