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

Terms

a(0) =2a(1) =-1a(2) =1a(3) =2a(4) =3a(5) =5a(6) =11a(7) =27a(8) =65a(9) =154a(10) =371a(11) =917a(12) =2303a(13) =5828a(14) =14839a(15) =38049a(16) =98237a(17) =255106a(18) =665655a(19) =1744318a(20) =4588881a(21) =12115727a(22) =32092597a(23) =85259160a(24) =227117149a(25) =606512641a(26) =1623412007a(27) =4354539253a(28) =11703442343a(29) =31512560472