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---
id: 5900f41a1000cf542c50ff2c
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title: >-
Problem 173: Using up to one million tiles how many different "hollow" square
laminae can be formed?
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challengeType: 5
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forumTopicId: 301808
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dashedName: >-
problem-173-using-up-to-one-million-tiles-how-many-different-hollow-square-laminae-can-be-formed
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---
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# --description--
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We shall define a square lamina to be a square outline with a square "hole" so that the shape possesses vertical and horizontal symmetry. For example, using exactly thirty-two square tiles we can form two different square laminae:
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< img class = "img-responsive center-block" alt = "two square lamina with holes 2x2 and 7x7" src = "https://cdn.freecodecamp.org/curriculum/project-euler/using-up-to-one-million-tiles-how-many-different-hollow-square-laminae-can-be-formed.gif" style = "background-color: white; padding: 10px;" >
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With one-hundred tiles, and not necessarily using all of the tiles at one time, it is possible to form forty-one different square laminae. Using up to one million tiles how many different square laminae can be formed?
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# --hints--
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`differentHollowSquareLaminae()` should return `1572729` .
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```js
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assert.strictEqual(differentHollowSquareLaminae(), 1572729);
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```
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# --seed--
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## --seed-contents--
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```js
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function differentHollowSquareLaminae() {
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return true;
}
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differentHollowSquareLaminae();
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```
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# --solutions--
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```js
// solution required
```