倒数阶乘之和

int jh = 10;
				                      double jc = 1;
				                      double sum = 0;
				                      double a = 1;                            

				                      while(jc <= jh)
				                      {

				                         a = a * jc;
				                         a = 1 / a;
				                         jc++;                                

				                         sum = sum + a;
				                    }
				                     System.out.println("阶乘和为:"+sum);