45 lines
922 B
Markdown
45 lines
922 B
Markdown
---
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id: 5900f3ef1000cf542c50ff01
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title: 'Problem 129: Repunit divisibility'
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challengeType: 5
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forumTopicId: 301756
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dashedName: problem-129-repunit-divisibility
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---
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# --description--
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A number consisting entirely of ones is called a repunit. We shall define R(k) to be a repunit of length k; for example, R(6) = 111111.
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Given that n is a positive integer and GCD(n, 10) = 1, it can be shown that there always exists a value, k, for which R(k) is divisible by n, and let A(n) be the least such value of k; for example, A(7) = 6 and A(41) = 5.
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The least value of n for which A(n) first exceeds ten is 17.
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Find the least value of n for which A(n) first exceeds one-million.
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# --hints--
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`euler129()` should return 1000023.
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```js
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assert.strictEqual(euler129(), 1000023);
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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 euler129() {
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return true;
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}
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euler129();
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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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