Challenge for you...

[Jack]

no chance to produce 100 primes with that lame formula unless you use bignum
here are the first 6 primes  

Code: (Select All)

Dim As Long i

For i = 1 To 6
    Print i, nprime(i)
Next

Function factorial# (n As Long)
    Dim As Long i
    Dim As Double f
    If n = 0 Or n = 1 Then
        factorial = 1
        Exit Function
    End If
    f = 1
    For i = 2 To n
        f = f * i
    Next
    factorial = f
End Function

Function nprime~&& (n As Long)
    Dim As Double s1, s2, s3, Pi: Pi = 3.1415926535897932384626433832795#
    Dim As Long i, j
    s1 = 0#
    For i = 1 To 2 ^ n
        s2 = 0#
        For j = 1 To i
            s3 = Cos(Pi * (factorial(j - 1) + 1) / j)
            s2 = s2 + Fix(s3 * s3)
        Next
        s1 = s1 + Fix(((n / s2) ^ (1 / n)))
    Next
    nprime = 1 + s1
End Function