Stephens' constant
In number theory, Stephens' constant expresses the density of certain subsets of the prime numbers. Let a {\displaystyle a} and b {\displaystyle b} be two multiplicatively independent integers, that is, a m b n ≠ 1 {\displaystyle a^{m}b^{n}\neq 1} except when both m {\displaystyle m} and n {\displaystyle n} equal zero.