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

[13, 8, 21, 24, 11, 41, 7, 4, 45, 35, 30, 31, 34, 16, 26, 42, 18, 2, 20, 46], target=51
[21, 30]