Plots unique number of ways to make an even number >= 4 out of two primes

Here is the result of running

goldbach(1000)

As a quick way to test this function, you can insert this function into Octave and run goldbach(500) at https://octave-online.net/.

In the future, it would be interesting to have a moving average plot that overlays on top of this graph to see how many different pairs of primes can be used to make any even number.