1.3 KiB
1.3 KiB
id | challengeType | title |
---|---|---|
5900f53d1000cf542c51004f | 5 | Problem 464: Möbius function and intervals |
Description
Let P(a,b) be the number of integers n in the interval [a,b] such that μ(n) = 1. Let N(a,b) be the number of integers n in the interval [a,b] such that μ(n) = -1. For example, P(2,10) = 2 and N(2,10) = 4.
Let C(n) be the number of integer pairs (a,b) such that: 1 ≤ a ≤ b ≤ n, 99·N(a,b) ≤ 100·P(a,b), and 99·P(a,b) ≤ 100·N(a,b).
For example, C(10) = 13, C(500) = 16676 and C(10 000) = 20155319.
Find C(20 000 000).
Instructions
Tests
tests:
- text: <code>euler464()</code> should return 198775297232878.
testString: 'assert.strictEqual(euler464(), 198775297232878, "<code>euler464()</code> should return 198775297232878.");'
Challenge Seed
function euler464() {
// Good luck!
return true;
}
euler464();
Solution
// solution required