851 B
851 B
id | title | challengeType | forumTopicId |
---|---|---|---|
5900f4c71000cf542c50ffd8 | Problem 346: Strong Repunits | 5 | 302005 |
--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.
--hints--
euler346()
should return 336108797689259260.
assert.strictEqual(euler346(), 336108797689259260);
--seed--
--seed-contents--
function euler346() {
return true;
}
euler346();
--solutions--
// solution required