1.4 KiB
1.4 KiB
id | challengeType | title |
---|---|---|
5900f5151000cf542c510028 | 5 | Problem 425: Prime connection |
Description
We call a prime P a 2's relative if there exists a chain of connected primes between 2 and P and no prime in the chain exceeds P.
For example, 127 is a 2's relative. One of the possible chains is shown below: 2 ↔ 3 ↔ 13 ↔ 113 ↔ 103 ↔ 107 ↔ 127 However, 11 and 103 are not 2's relatives.
Let F(N) be the sum of the primes ≤ N which are not 2's relatives. We can verify that F(103) = 431 and F(104) = 78728.
Find F(107).
Instructions
Tests
tests:
- text: <code>euler425()</code> should return 46479497324.
testString: assert.strictEqual(euler425(), 46479497324, '<code>euler425()</code> should return 46479497324.');
Challenge Seed
function euler425() {
// Good luck!
return true;
}
euler425();
Solution
// solution required