一、由给定数列邀an妖的前n项,求数列的通项公式数列是定义在N*或邀1,2,……,n妖上的函数,同熟悉基本初等函数一样,熟知一些常见数列的通项公式,如:直线型,an=2n+1,an=2n-1,二次型an=n2;指数型,an=2n,an=10n,an=(1/2)n First, by the given number of invited an ancestors of the demon n, the number of columns of the general formula is defined in the N * or invited 1,2, ..., n demon function, familiar with the basic elementary functions, familiar with some An ordinary series of common terms, such as: linear, an = 2n +1, an = 2n-1, quadratic an = n2; exponential, an = 2n, an = 10n, an = (1/2) n