2018-09-30 23:01:58 +01:00
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---
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id: 5900f4551000cf542c50ff68
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title: 'Problem 233: Lattice points on a circle'
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2020-11-27 19:02:05 +01:00
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challengeType: 5
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2019-08-05 09:17:33 -07:00
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forumTopicId: 301877
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2018-09-30 23:01:58 +01:00
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---
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2020-11-27 19:02:05 +01:00
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# --description--
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2018-09-30 23:01:58 +01:00
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2020-11-27 19:02:05 +01:00
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Let f(N) be the number of points with integer coordinates that are on a circle passing through (0,0), (N,0),(0,N), and (N,N).
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2018-09-30 23:01:58 +01:00
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2020-11-27 19:02:05 +01:00
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It can be shown that f(10000) = 36.
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2018-09-30 23:01:58 +01:00
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2020-11-27 19:02:05 +01:00
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What is the sum of all positive integers N ≤ 1011 such that f(N) = 420 ?
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2018-09-30 23:01:58 +01:00
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2020-11-27 19:02:05 +01:00
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# --hints--
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2018-09-30 23:01:58 +01:00
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2020-11-27 19:02:05 +01:00
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`euler233()` should return 271204031455541300.
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2018-09-30 23:01:58 +01:00
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2020-11-27 19:02:05 +01:00
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```js
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assert.strictEqual(euler233(), 271204031455541300);
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2018-09-30 23:01:58 +01:00
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```
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2020-11-27 19:02:05 +01:00
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# --seed--
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2018-09-30 23:01:58 +01:00
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2020-11-27 19:02:05 +01:00
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## --seed-contents--
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2018-09-30 23:01:58 +01:00
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```js
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function euler233() {
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2020-09-15 09:57:40 -07:00
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2018-09-30 23:01:58 +01:00
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return true;
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}
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euler233();
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```
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2020-11-27 19:02:05 +01:00
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# --solutions--
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2018-09-30 23:01:58 +01:00
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```js
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// solution required
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```
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