a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-1)*a(1) for n >= 5, starting 1,0,1,1.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =2a(5) =5a(6) =12a(7) =29a(8) =72a(9) =182a(10) =466a(11) =1207a(12) =3158a(13) =8334a(14) =22158a(15) =59299a(16) =159614a(17) =431838a(18) =1173710a(19) =3203244a(20) =8774780a(21) =24118522a(22) =66497316a(23) =183858411a(24) =509670494a(25) =1416231616a(26) =3944027402a(27) =11006186760a(28) =30772507128a(29) =86191006746