(1,2,3,4,...,n)

Math Junior
1

If n is an even positive integer. Prove that the set (1,2,\dots,n) can be divided into n distinct pairs such that the sum of numbers in each pair equals a prime number.

2 Likes
2

Do you mean the set \{1,2,3, \cdots ,2n\} ?

or you mean \frac{n}{2} pairs?

3

n/2