A Goldbach partition of an even integer is an unordered pair of primes such that (Oliveira e Silva). Letting denote the number of Goldbach partitions of without regard to order, the number of ways of writing as a sum of two prime numbers taking
the order of the two primes into account is
(1)
The Goldbach conjecture is then equivalent to the statement that or, equivalently, that , for every even integer .
A plot of ,
sometimes known as Goldbach's comet, for up to 2000 is illustrated above.
The following table summarizes the values of several variants of for , 4, ....