Problem 601

[FourLegsDriveCat]

Hi,
It's rather suggestion, not clarification.
Problem says:

the smallest positive integer k such that n+k is not divisible by k+1

Since k starts from 1, the following examples seem unnecessary:

13 is divisible by 1
120 is divisible by 1

[jaap]

I disagree. $k$ is essentially the length of the streak, i.e. how many consecutive lines in the two examples have divisibility before the line where it is no longer divisible. Like a lucky streak, it is about how long you can keep it going before your luck runs out. The divisibility by 1 is part of that, regardless of the fact that a streak can never have length zero.

[FourLegsDriveCat]

OK, makes sense, just confusing a bit when first read.