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---
id: 5900f3e41000cf542c50fef7
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title: 'Problema 120: Resti di quadrati'
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challengeType: 5
forumTopicId: 301747
dashedName: problem-120-square-remainders
---
# --description--
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Sia `r` il resto quando ${(a − 1)}^n + {(a + 1)}^n$ viene diviso per $a^2$.
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Per esempio, se $a = 7$ e $n = 3$, allora $r = 42: 6^3 + 8^3 = 728 ≡ 42 \\ \text{mod}\\ 49$. E se `n` varia, allora anche `r` varia, ma per $a = 7$ risulta che $r_{max} = 42$.
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Per $3 ≤ a ≤ 1000$, trova $\sum{r}_{max}$.
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# --hints--
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`squareRemainders()` dovrebbe restituire `333082500` .
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```js
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assert.strictEqual(squareRemainders(), 333082500);
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```
# --seed--
## --seed-contents--
```js
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function squareRemainders() {
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return true;
}
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squareRemainders();
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```
# --solutions--
```js
// solution required
```