MathDB

Given an integer

n > 2

, give an example of a set of

n

mutually different numbers

a_1,...,a_n

for which the set of their pairwise sums

a_i + a_j

(

i \ne j

) contains as few different numbers as possible; also give an example of a set of n different numbers

b_1,...,b_n

for which the set of their pairwise sums

b_i+b_j

(

i \ne j

) contains as many different numbers as possible;

4