You are given a list of integers and an integer target, return a list of a pair of numbers in any order such that they add up to target. If there is no such pair of numbers, then return an empty list

[15, 1, 3, 11, 8, 40, 4, 21, 17, 30, 23, 9, 45, 5, 25, 18, 42, 39, 22, 2], target=38
[21, 17]