由于数列是一种特殊的函数,所以数列中也存在着周期问题.对于有些数列题,表面上看与周期无关,但实际上却隐含着周期性,一旦揭示了其周期,问题便可迎刃而解.本文拟例说明解答此类问题的基本策略,以供参考. Since the series is a special kind of function, there are also periodic problems in the series. For some series of numbers, it is irrelevant to the cycle on the surface, but it actually implies periodicity. Once the cycle is revealed, the problem can be solved. This article is intended to illustrate the basic strategies for answering such questions for reference.