(091) T2

Part of 1985 Tournament Of Towns

Problems(1)

TOT 091 1985 Spring Train S2 largest subset with diff, of any 2 not prime

Source:

From the set of numbers

1 , 2, 3, . . . , 1985

choose the largest subset such that the difference between any two numbers in the subset is not a prime number (the prime numbers are

2, 3 , 5 , 7,... , 1

is not a prime number) .

DifferenceprimeCompositenumber theorycombinatoricsmaximum