2021-06-15 00:49:18 -07:00
---
id: 5900f4e61000cf542c50fff9
2021-11-23 11:06:14 -08:00
title: 'Problema 378: Trios de triângulos'
2021-06-15 00:49:18 -07:00
challengeType: 5
forumTopicId: 302040
dashedName: problem-378-triangle-triples
---
# --description--
2021-11-23 11:06:14 -08:00
Considere $T(n)$ como o $n^{\text{º}}$ número triangular. Assim, $T(n) = \frac{n(n + 1)}{2}$.
2021-06-15 00:49:18 -07:00
2021-11-23 11:06:14 -08:00
Considere $dT(n)$ como o número de divisores de $T(n)$. Ex.: $T(7) = 28$ e $dT(7) = 6$.
2021-06-15 00:49:18 -07:00
2021-11-23 11:06:14 -08:00
Considere $Tr(n)$ como o número de trios ($i$, $j$, $k$), tal que $1 ≤ i < j < k ≤ n$ e $dT(i) > dT(j) > dT(k)$. $Tr(20) = 14$, $Tr(100) = 5.772$ e $Tr(1000) = 11.174.776$.
2021-06-15 00:49:18 -07:00
2021-11-29 08:32:04 -08:00
Encontre $Tr(60.000.000)$. Dê os últimos 18 algarismos da sua resposta.
2021-06-15 00:49:18 -07:00
# --hints--
2021-11-23 11:06:14 -08:00
`triangleTriples()` deve retornar `147534623725724700` .
2021-06-15 00:49:18 -07:00
```js
2021-11-23 11:06:14 -08:00
assert.strictEqual(triangleTriples(), 147534623725724700);
2021-06-15 00:49:18 -07:00
```
# --seed--
## --seed-contents--
```js
2021-11-23 11:06:14 -08:00
function triangleTriples() {
2021-06-15 00:49:18 -07:00
return true;
}
2021-11-23 11:06:14 -08:00
triangleTriples();
2021-06-15 00:49:18 -07:00
```
# --solutions--
```js
// solution required
```