First Hardy–Littlewood conjecture
In number theory, the first Hardy–Littlewood conjecture states the asymptotic formula for the number of prime k-tuples less than a given magnitude by generalizing the prime number theorem. It was first proposed by G. H. Hardy and John Edensor Littlewood in 1923.
Statement
Let be positive even integers such that the numbers of the sequence do not form a complete residue class with respect to any prime and let denote the number of primes less than so that are all prime. Thenwhere
is a product over odd primes and denotes the number of distinct residues of modulo.
The case and is related to the twin prime conjecture. Specifically if denotes the number of twin primes less than n then
where
is the twin prime constant.
Skewes' number
The Skewes' numbers for prime k-tuples are an extension of the definition of Skewes' number to prime k-tuples based on the first Hardy–Littlewood conjecture. The first prime p that violates the Hardy–Littlewood inequality for the k-tuple P, i.e., such thatis the Skewes number for P.