Primes

Useful collection of tools for .NET Core that handlies prime numbers. Very big prime numbers (BigInteger).

Api / Docs

Testing primality

var someBigNBumber = new BigInteger("2391030138092183021830123");
var isPrime = await someBigNumber.IsPrimeAsync(new RobinMillerTest(complexity: 50))

Available test algorithms:

• Miller–Rabin test
• Fermat test
• Solovay-Strassen test
• Naive test

Implementing own test

You can create own test. All you need is to implement interface:

public interface IPrimalityTest
{
    Task<bool> TestAsync(BigInteger source);
}

You can also use helper class:

public abstract class PrimalityTest: IPrimalityTest
{
}

It has bunch of methods that can be useful for testing.

Generating primes

PrimaryBigInteger class contains some methods like generating prime numbers:

public static Task<BigInteger> GeneratePrime(uint bitLength, IRandomProvider randomProvider, IPrimalityTest primalityTest)
public static Task<BigInteger> GenerateProbablyPrime(uint bitLength)

Mersenne sequence

MersenneSequence is a class, that contains bunch of methods for handling that sequence:

public static BigInteger Value(int n)

Generates a value of n-th mersenne number

public static IEnumerable<BigInteger> Generate(int count = int.MaxValue)

Generates an enumerable that contains a specified count of mersenne numbers

public static Task<bool> IsPrimeAsync(int n)

Checkes wheter n-th mersenne number is prime or not