--- 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: 18 balanced sculptures of order 6 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 ```