public void Start()
{
int max = 10000;
var composites = PrimeNumbers.GetCompositeNumbers(max);
var primes = PrimeNumbers.GetPrimes(max);
for (int c = 0; c < composites.Length; c++)
{
if (composites[c] % 2 == 0)
{
continue;
}
bool doable = false;
for (int n = 1; n < Math.Sqrt(0.5 * composites[c]); n++)
{
for (int p = 1; p < primes.Length && primes[p] <= composites[c] - 2 * n * n; p++)
{
if (composites[c] == primes[p] + 2 * n * n)
{
doable = true;
//Console.WriteLine($"{composites[c]} = {primes[p]} + 2 x {n}^2");
}
if (doable)
{
break;
}
}
if (doable)
{
break;
}
}
if (!doable)
{
Console.WriteLine($"Not doable! {composites[c]}");
break;
}
}
}