public class Ninetheen {
	/*求1+2!+3!+...+20!的和*/
	public static void main(String[] args){
		int i,j;
		long  sum=0,jiecheng=1;
		for(i=1;i<=20;i++){
			jiecheng=1;
			for(j=1;j<=i;j++)
				jiecheng=jiecheng*j;
			sum=sum+jiecheng;
		}
		System.out.println("1+2!+3!+...+20!的和是:"+sum);
		
	}
}
原文:http://www.cnblogs.com/yjh123/p/6352235.html