Prime Numbers

A prime number is a whole number greater than 1 that has no positive divisors other than itself and 1
A whole number greater than 1 that is not prime is called a composite number.
A simple (but slow) method for determining prime numbers is called "trial division"
This consists of testing whether "n" is a multiple of any integer between 2 and SQRT(n)


Public Function PrimeNumbers(ByVal iMaxNumbers As Integer) As Variant 
   Dim myarray As Variant
   Dim iprimecount As Integer
   Dim number As Long
   Dim divisor As Long
   Dim maxdivisor As Long
   Dim isprime As Boolean

   ReDim myarray(1 to MaxNumber, 1 to 2)
   iprimecount = 1
   For number = 1 to iMaxNumber
      Select Case number
         Case Is < 2
            isprime = False
        Case Is = 2
            isprime = True
            myarray(iprimecount,1) = number
            iprimecount = iprimecount + 1
        Case Is > 2
            isprime = True
            If number Mod 2 = 0 Then
                isprime = False
            Else
                  maxdivisor = CLnd(Sqr(number))
                   divisor = 3
                   Do While (divisor <= maxdivisor)
                       If (number Mod divisor = 0) Then
                          isprime = False
                          Exit Do
                       End If
                       divisor = divisor + 1
                   Loop
               End If
               If (isprime = True) Then
                   myarray(ipriecount, 1) = number
                   iprimecount = iprimecount + 1
               End If
          End Select
          If (isprime = True) Then
'MsgBox number & " is prime"
          Else
'MsgBox number & " is not prime"
         End If
     Next number
   PrimeNumbers = myarray
End Function



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