1005 B
1005 B
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f4181000cf542c50ff2a | Problem 171: Finding numbers for which the sum of the squares of the digits is a square | 5 | 301806 | problem-171-finding-numbers-for-which-the-sum-of-the-squares-of-the-digits-is-a-square |
--description--
For a positive integer n
, let f(n)
be the sum of the squares of the digits (in base 10) of n
, e.g.
\begin{align}
& f(3) = 3^2 = 9 \\\\
& f(25) = 2^2 + 5^2 = 4 + 25 = 29 \\\\
& f(442) = 4^2 + 4^2 + 2^2 = 16 + 16 + 4 = 36 \\\\
\end{align}$$
Find the last nine digits of the sum of all $n$, $0 < n < {10}^{20}$, such that $f(n)$ is a perfect square.
# --hints--
`lastDigitsSumOfPerfectSquare()` should return `142989277`.
```js
assert.strictEqual(lastDigitsSumOfPerfectSquare(), 142989277);
```
# --seed--
## --seed-contents--
```js
function lastDigitsSumOfPerfectSquare() {
return true;
}
lastDigitsSumOfPerfectSquare();
```
# --solutions--
```js
// solution required
```