求斐波那契数列中第n个数，斐波那契数，亦称之为斐波那契数列（意大利语： Successione di Fibonacci)，又称黄金分割数列、费波那西数列、费波拿契数、费氏数列，

指的是这样一个数列：0、1、1、2、3、5、8、13、21、……

在数学上，斐波纳契数列以如下被以递归的方法定义：F0=0，F1=1，Fn=F(n-1)+F(n-2)（n>=2，n∈N*），

用文字来说，就是斐波那契数列列由 0 和 1 开始，之后的斐波那契数列系数就由之前的两数相加。-N in the Fibonacci sequence number, Fibonacci number, also referred to as the Fibonacci sequence (Italian: Successione di Fibonacci), also known as the golden sequence, its the west and its number, Karl fischer series,

Refers to such a sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21,...

In mathematics, Fibonacci sequence in the following is defined by recursive method: F0 = 0, F1 = 1, Fn = F (n- 1)+ F (n- 2) (n > = 2, n ∈ n*).

In words, is the Fibonacci sequence of 0 s and 1 s start, after the Fibonacci sequence coefficient by the previous two Numbers together.