练习题来源:

https://projecteuler.net/archives

Problem 2

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.


问题2:

   斐波那契数列的规则是:后一个数字是前两个数字之和,如前十个斐波那契数列为:

        1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

   那么根据其规律,找出400,0000以内的斐波那契数,计算其偶数之和