static void Main(string[] args)
{
var primeGenerator = new CachedPrimeNumberGenerator(new SievePrimeNumberGenerator());
var primes = primeGenerator.GetPrimesBelowLongMaxValue();
long[] results = new long[11];
int index = 0;
foreach (var prime in primes.SkipWhile(p => p <= 7))
{
if (IsTruncatableLeft(prime, primeGenerator) &&
IsTruncatableRight(prime, primeGenerator))
{
results[index++] = prime;
Console.WriteLine("Found {0} ({1}/11)", prime, index);
if (index == 11)
{
break;
}
}
}
Console.WriteLine(results.Sum());
Console.ReadKey();
}
private static PrimesCount CountPrimes(int a, int b)
{
var retVal = new PrimesCount
{
NumPrimes = -1,
A = a,
B = b
};
IEnumerable <long> primes;
long result = 0;
int n = 0;
do
{
retVal.NumPrimes++;
result = n * n + a * n + b;
primes = generator.GetPrimesBelowLongMaxValue().TakeWhile(p => p <= result);
n++;
}while (primes.Contains(result));
return(retVal);
}
static void Main(string[] args)
{
CachedPrimeNumberGenerator generator = new CachedPrimeNumberGenerator(new SievePrimeNumberGenerator());
int current = 9;
while (true)
{
var primes = generator.GetPrimesBelowLongMaxValue().TakeWhile(p => p <= current).ToList();
if (!primes.Contains(current))
{
if (!IsGoldbachComposit(primes, current))
{
Console.WriteLine(current);
Console.ReadKey();
break;
}
}
current += 2;
}
}
