∫0xⅇ-t⁢In⁡(t)⁢ⅆ⁡t=x⁢ⅇ-x⁢(I0⁡(x)+I1⁡(x))+n⁢(ⅇ-x⁢I0⁡(x)-1)+2⁢ⅇ-x⁢∑k=1n-1(n-k)⁢Ik⁡(x),