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curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-346-strong-repunits.md

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+---
+id: 5900f4c71000cf542c50ffd8
+challengeType: 5
+title: 'Problem 346: Strong Repunits'
+forumTopicId: 302005
+---
+
+## Description
+<section id='description'>
+The number 7 is special, because 7 is 111 written in base 2, and 11 written in base 6 (i.e. 710 = 116 = 1112). In other words, 7 is a repunit in at least two bases b > 1.
+
+
+We shall call a positive integer with this property a strong repunit. It can be verified that there are 8 strong repunits below 50:  {1,7,13,15,21,31,40,43}. Furthermore, the sum of all strong repunits below 1000 equals 15864.
+
+Find the sum of all strong repunits below 1012.
+</section>
+
+## Instructions
+<section id='instructions'>
+
+</section>
+
+## Tests
+<section id='tests'>
+
+```yml
+tests:
+  - text: <code>euler346()</code> should return 336108797689259260.
+    testString: assert.strictEqual(euler346(), 336108797689259260);
+
+```
+
+</section>
+
+## Challenge Seed
+<section id='challengeSeed'>
+
+<div id='js-seed'>
+
+```js
+function euler346() {
+
+  return true;
+}
+
+euler346();
+```
+
+</div>
+
+
+
+</section>
+
+## Solution
+<section id='solution'>
+
+```js
+// solution required
+```
+
+</section>