a(1)=-1;
a(2)=-3;
a(3)=-det Toeplitz矩阵((3,2),(3,5))=1;
a(4)=-det Toeplitz矩阵((3,2,1),(3,5,7))=1;
a(5)=-det Toeplitz矩阵((3,2,1,0),(3,5,7,11))=-1;
a(6)=-det Toeplitz矩阵((3,2,1,0,0),(3,5,7,11,13))=5;
a(7)=-det Toeplitz矩阵((3,2,1,0,0,0),(3,5,7,11,13,17))=-19。