MathDB

sum of any 3 of n is a prime, max n wanted

Source: New Zealand MO 2021 Round 2 p3 NZMO

October 6, 2021

number theoryprime

Problem Statement

Let

\{x_1, x_2, x_3, ..., x_n\}

be a set of

n

distinct positive integers, such that the sum of any

3

of them is a prime number. What is the maximum value of

n