Task: Mersenne primes
Python: import random


def MillerRabinPrimalityTest(number):
    
    if number == 2:
        return True
    elif number == 1 or number % 2 == 0:
        return False
    
    
    
    
    oddPartOfNumber = number - 1
    
    
    timesTwoDividNumber = 0
    
    
    while oddPartOfNumber % 2 == 0:
        oddPartOfNumber = oddPartOfNumber / 2
        timesTwoDividNumber = timesTwoDividNumber + 1 
     
    
    for time in range(3):
        
        
        while True:
            
            randomNumber = random.randint(2, number)-1
            if randomNumber != 0 and randomNumber != 1:
                break
        
        
        randomNumberWithPower = pow(randomNumber, oddPartOfNumber, number)
        
        
        if (randomNumberWithPower != 1) and (randomNumberWithPower != number - 1):
            
            iterationNumber = 1
            
            
            while (iterationNumber <= timesTwoDividNumber - 1) and (randomNumberWithPower != number - 1):
                
                randomNumberWithPower = pow(randomNumberWithPower, 2, number)
                
                
                iterationNumber = iterationNumber + 1
            
            if (randomNumberWithPower != (number - 1)):
                return False
            
    
    return True


MAX = 20
p = 2
count = 0
while True:
    m = (2 << (p - 1)) - 1
    if MillerRabinPrimalityTest(m):
        print "2 ^ {} - 1".format(p)
        count = count + 1
        if count == MAX:
            break
    
    while True:
        p = p + 2 if (p > 2) else 3
        if MillerRabinPrimalityTest(p):
            break
print "done"

VB: Imports System.Numerics

Module Module1

    Function Sqrt(x As BigInteger) As BigInteger
        If x < 0 Then
            Throw New ArgumentException("Negative argument.")
        End If
        If x < 2 Then
            Return x
        End If
        Dim y = x / 2
        While y > (x / y)
            y = ((x / y) + y) / 2
        End While
        Return y
    End Function

    Function IsPrime(bi As BigInteger) As Boolean
        If bi < 2 Then
            Return False
        End If
        If bi Mod 2 = 0 Then
            Return bi = 2
        End If
        If bi Mod 3 = 0 Then
            Return bi = 3
        End If
        If bi Mod 5 = 0 Then
            Return bi = 5
        End If
        If bi Mod 7 = 0 Then
            Return bi = 7
        End If
        If bi Mod 11 = 0 Then
            Return bi = 11
        End If
        If bi Mod 13 = 0 Then
            Return bi = 13
        End If
        If bi Mod 17 = 0 Then
            Return bi = 17
        End If
        If bi Mod 19 = 0 Then
            Return bi = 19
        End If

        Dim limit = Sqrt(bi)
        Dim test As BigInteger = 23
        While test < limit
            If bi Mod test = 0 Then
                Return False
            End If
            test += 2
            If bi Mod test = 0 Then
                Return False
            End If
            test += 4
        End While

        Return True
    End Function

    Sub Main()
        Const MAX = 9

        Dim pow = 2
        Dim count = 0

        While True
            If IsPrime(pow) Then
                Dim p = BigInteger.Pow(2, pow) - 1
                If IsPrime(p) Then
                    Console.WriteLine("2 ^ {0} - 1", pow)
                    count += 1
                    If count >= MAX Then
                        Exit While
                    End If
                End If
            End If
            pow += 1
        End While
    End Sub

End Module