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, 1, 0.

Terms

a(0) =0a(1) =1a(2) =1a(3) =0a(4) =1a(5) =1a(6) =1a(7) =3a(8) =3a(9) =6a(10) =11a(11) =15a(12) =31a(13) =50a(14) =85a(15) =161a(16) =267a(17) =490a(18) =883a(19) =1548a(20) =2863a(21) =5127a(22) =9307a(23) =17116a(24) =31021a(25) =57123a(26) =104963a(27) =192699a(28) =356643a(29) =658034