编写方法，输出n以内的所有完数。

完数：如果一个数恰好等于它的因子之和，则这个数就是“完数”。例如：6的因子是1、2、3，而6=1+2+3，因此6就是完数。

-The preparation method, all within a few finished output n. Ends count: If a number is exactly equal to the sum of its factor, then this number is the " complete count."　For example: factor 6 is 1,2,3, and 6 = 1+2+3, so the number 6 is finished.