exp(x)=(1+x)*(1+x^2/2!)*(1-2*x^3/3!)** (1+130*x个^6/6!)*(1-720*x个^7/7!)*(1+8505*x个^8/8!)*(1-35840*x个^9/9!)*(1+412776*x个^10/10!)*(1-3628800*x个^11/11!)*...*(1+一(n个)*x个^n个/n个!)*...
(1+130*x^6/6!)*(1-720*x^7/7!)**
(1+412776*x^10/10!)*(1-3628800*x^11/11!)**(1+a(n)*x^n/n!)*。。。