---
id: 5900f4801000cf542c50ff92
title: 'Problem 275: Balanced Sculptures'
challengeType: 5
forumTopicId: 301925
dashedName: problem-275-balanced-sculptures
---
# --description--
Let us define a balanced sculpture of order $n$ as follows:
- A polyomino made up of $n + 1$ tiles known as the blocks ($n$ tiles) and the plinth (remaining tile);
- the plinth has its centre at position ($x = 0$, $y = 0$);
- the blocks have $y$-coordinates greater than zero (so the plinth is the unique lowest tile);
- the centre of mass of all the blocks, combined, has $x$-coordinate equal to zero.
When counting the sculptures, any arrangements which are simply reflections about the $y$-axis, are not counted as distinct. For example, the 18 balanced sculptures of order 6 are shown below; note that each pair of mirror images (about the $y$-axis) is counted as one sculpture:
There are 964 balanced sculptures of order 10 and 360505 of order 15.
How many balanced sculptures are there of order 18?
# --hints--
`balancedSculptures()` should return `15030564`.
```js
assert.strictEqual(balancedSculptures(), 15030564);
```
# --seed--
## --seed-contents--
```js
function balancedSculptures() {
return true;
}
balancedSculptures();
```
# --solutions--
```js
// solution required
```