数码4次方求和迭代的黑洞数

The Periodic Points of Iteration of Each Digit's Biquadratic Sum of Natural Number

数码4次方求和迭代有且仅有4个不动点,一对2周期点和7个7周期点。自然数经过若干次数码4次方求和迭代进入各个不动点或周期点的概率并不均衡的,其中绝大多数进入7周期点。

There are only four fixed, a pair of 2- period and seven 7- period points in the iteration of sum iteration of the fourth power of each digit of natural number. Through several sum iteration of the fourth power of digital number, probabilities of every fixed or periodic points are unbalanced, where most of the numbers enter 7-period points.