The Postage Stamp Problem: An algorithm to determine the h-range on the h-range formula on the extremal basis problem for k = 4

Given an integral “stamp” basis Ak with 1 = a1 < a2 < . . . < ak and a positive integer h, we define the h-range n(h, Ak) as n(h, Ak) = max{N ∈ N | n ≤ N =⇒ n = k ∑