4

Part of 2016 Brazil National Olympiad

Problems(1)

Integers without distances 1,2,6 between them

Source: 38th Brazilian MO (2016) - Second Day - Problem 4

What is the greatest number of positive integers lesser than or equal to 2016 we can choose such that it doesn't have two of them differing by 1,2, or 6?

Brazilian Math Olympiad 2016combinatorics