From fundamental unit of Z[ (-n)^1/4 ].

Terms

a(0) =-1a(1) =1a(2) =1a(3) =-1a(4) =-4a(5) =9a(6) =-2a(7) =0a(8) =-1a(9) =-45a(10) =4a(11) =3a(12) =2a(13) =-7a(14) =0a(15) =-1a(16) =-36792a(17) =-11320425a(18) =-2a(19) =-24a(20) =-267972a(21) =352849a(22) =-10a(23) =0a(24) =17a(25) =135531a(26) =-12a(27) =189709a(28) =-21012a(29) =-371631