任给一个自然数，若为偶数除以2，若为奇数则乘3加1，得到一个新的自然数后按照上面的法则继续演算，若干次后得到的结果必然为1-Either to a natural number, if it is even divided by two, if odd then by 3 plus 1, to get a new natural numbers, in accordance with the above rules to continue to calculus, the results obtained after a number of inevitable for a