45 lines
915 B
Markdown
45 lines
915 B
Markdown
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---
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id: 5900f5111000cf542c510023
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title: 'Problem 420: 2x2 positive integer matrix'
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challengeType: 5
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forumTopicId: 302090
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dashedName: problem-420-2x2-positive-integer-matrix
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---
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# --description--
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A positive integer matrix is a matrix whose elements are all positive integers.
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Some positive integer matrices can be expressed as a square of a positive integer matrix in two different ways. Here is an example:
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We define F(N) as the number of the 2x2 positive integer matrices which have a trace less than N and which can be expressed as a square of a positive integer matrix in two different ways. We can verify that F(50) = 7 and F(1000) = 1019.
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Find F(107).
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# --hints--
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`euler420()` should return 145159332.
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```js
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assert.strictEqual(euler420(), 145159332);
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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 euler420() {
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return true;
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}
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euler420();
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```
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# --solutions--
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```js
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// solution required
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```
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