freeCodeCamp/curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-197-investigating-the-behaviour-of-a-recursively-defined-sequence.md

id, challengeType, videoUrl, title

id	challengeType	videoUrl	title
5900f4311000cf542c50ff44	5		问题197：研究递归定义的序列的行为

Description

给定函数f（x）=⌊230.403243784-x2⌋×10-9（⌊⌊是floor函数），序列un由u0 = -1和un + 1 = f（un）定义。

找到n + 1012的un + un + 1.在小数点后面给出9位数的答案。

Instructions

Tests

tests:
  - text: <code>euler197()</code>应该返回1.710637717。
    testString: assert.strictEqual(euler197(), 1.710637717);

Challenge Seed

function euler197() {
  // Good luck!
  return true;
}

euler197();

Solution

// solution required

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