freeCodeCamp/problem-337-totient-stairstep-sequences.chinese.md at ff8db8ce9e8413f490626e1572e7fd09825db39c

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id, challengeType, title, videoUrl, localeTitle

id	challengeType	title	videoUrl	localeTitle
5900f4be1000cf542c50ffd0	5	Problem 337: Totient Stairstep Sequences		问题337欧拉序列阶梯

Description

令{a1，a2，...，an}为长度为n的整数序列，使得：a1 = 6，对于所有1≤i<n：φ（ai）<φ（ai + 1）<ai <ai + 11令S（N）为具有≤N的这种序列的数目。例如，S（10）= 4：{6}，{6,8}，{6,8,9}和{6,10}。我们可以验证S（100）= 482073668和S（10 000）mod 108 = 73808307。

找到S（20 000 000）mod 108。

1φ表示欧拉的函数。

Instructions

Tests

tests:
  - text: <code>euler337()</code>应该返回85068035。
    testString: assert.strictEqual(euler337(), 85068035);

Challenge Seed

function euler337() {
  // Good luck!
  return true;
}

euler337();

Solution

// solution required

/section>

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