1000 B
1000 B
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f3ef1000cf542c50ff01 | Problem 129: Repunit divisibility | 5 | 301756 | problem-129-repunit-divisibility |
--description--
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
.
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
.
The least value of n
for which A(n)
first exceeds ten is 17.
Find the least value of n
for which A(n)
first exceeds one-million.
--hints--
repunitDivisibility()
should return 1000023
.
assert.strictEqual(repunitDivisibility(), 1000023);
--seed--
--seed-contents--
function repunitDivisibility() {
return true;
}
repunitDivisibility();
--solutions--
// solution required