y=(x+1)/(x²-5x+4)=(5/3)*[1/(x-4)]-(2/3)*[1/(x-1)];
其中n接导数[1/(x-a)]('n)=(-1)^n*n!*[1/(x-a)^(n+1)];
∴y('n)=(5/3)*(-1)^n*n![1/(x-4)^(n+1)]-(2/3)*(-1)^n*n!*[1/(x-1)^(n+1)];
当x=0,y('n)=(5/3)*n!*[(-1)^n/(-4)^(n+1)]-(2/3)*n!*[(-1)^n/(-1)^(n+1)]={[-(5/12)/4^n]+(2/3)}n!;