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Problem 234: Semidivisible numbers

curriculum/challenges/english/blocks/project-euler-problems-201-to-300/5900f4571000cf542c50ff69.md

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--description--

For an integer $n ≥ 4$, we define the lower prime square root of $n$, denoted by $lps(n)$, as the $\text{largest prime} ≤ \sqrt{n}$ and the upper prime square root of $n$, $ups(n)$, as the $\text{smallest prime} ≥ \sqrt{n}$.

So, for example, $lps(4) = 2 = ups(4)$, $lps(1000) = 31$, $ups(1000) = 37$.

Let us call an integer $n ≥ 4$ semidivisible, if one of $lps(n)$ and $ups(n)$ divides $n$, but not both.

The sum of the semidivisible numbers not exceeding 15 is 30, the numbers are 8, 10 and 12. 15 is not semidivisible because it is a multiple of both $lps(15) = 3$ and $ups(15) = 5$. As a further example, the sum of the 92 semidivisible numbers up to 1000 is 34825.

What is the sum of all semidivisible numbers not exceeding 999966663333?

--hints--

semidivisibleNumbers() should return 1259187438574927000.

js
assert.strictEqual(semidivisibleNumbers(), 1259187438574927000);

--seed--

--seed-contents--

js
function semidivisibleNumbers() {

  return true;
}

semidivisibleNumbers();

--solutions--

js
// solution required