A Mathematical Haystack Without Fifth Powers.

The article discusses the mathematical haystack, which was defined as an infinite sequence of positive integers that hides all number except a set of prime numbers. The reprint number is one example of a mathematical haystack as its sequence creates a haystack that comes from the little theorem of Fermat, which states that p is a prime and a, p are relatively prime, then every prime number besides 2 or 5 is a divisor of a reprint number.