bd68b70f3d
* fix: remove isHidden flag from frontmatter * fix: add isUpcomingChange Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com> * feat: hide blocks not challenges Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com> Co-authored-by: Ahmad Abdolsaheb <ahmad.abdolsaheb@gmail.com>
76 lines
1.0 KiB
Markdown
76 lines
1.0 KiB
Markdown
---
|
||
id: 5900f4e61000cf542c50fff9
|
||
challengeType: 5
|
||
title: 'Problem 378: Triangle Triples'
|
||
forumTopicId: 302040
|
||
---
|
||
|
||
## Description
|
||
<section id='description'>
|
||
Let T(n) be the nth triangle number, so T(n) =
|
||
|
||
|
||
n (n+1)2
|
||
|
||
.
|
||
|
||
|
||
Let dT(n) be the number of divisors of T(n).
|
||
E.g.:
|
||
T(7) = 28 and dT(7) = 6.
|
||
|
||
|
||
Let Tr(n) be the number of triples (i, j, k) such that 1 ≤ i < j < k ≤ n and dT(i) > dT(j) > dT(k).
|
||
Tr(20) = 14, Tr(100) = 5772 and Tr(1000) = 11174776.
|
||
|
||
|
||
Find Tr(60 000 000).
|
||
Give the last 18 digits of your answer.
|
||
</section>
|
||
|
||
## Instructions
|
||
<section id='instructions'>
|
||
|
||
</section>
|
||
|
||
## Tests
|
||
<section id='tests'>
|
||
|
||
```yml
|
||
tests:
|
||
- text: <code>euler378()</code> should return 147534623725724700.
|
||
testString: assert.strictEqual(euler378(), 147534623725724700);
|
||
|
||
```
|
||
|
||
</section>
|
||
|
||
## Challenge Seed
|
||
<section id='challengeSeed'>
|
||
|
||
<div id='js-seed'>
|
||
|
||
```js
|
||
function euler378() {
|
||
// Good luck!
|
||
return true;
|
||
}
|
||
|
||
euler378();
|
||
```
|
||
|
||
</div>
|
||
|
||
|
||
|
||
</section>
|
||
|
||
## Solution
|
||
<section id='solution'>
|
||
|
||
```js
|
||
// solution required
|
||
```
|
||
|
||
</section>
|