n!=n×(n−1)×(n−2)×⋅⋅⋅

[Wazyo]

I need to do this in excel with vba for school.
Create a subroutine Factorial that creates an array of size n. The first element ofthe array is 1. The next element is 1*2. Next is 1*2*3, etc. Formula: for n>1, ifelement ‘n’ is x then Xn = Xn-1 * n.
For example, Factorial(6) creates this array:

1 2 6 24 120 720

 

[shg]

And what have you tried so far?

 

[Rick Rothstein]

Is this a homework assignment? If so, we don't do homework for you. After all, what do you learn if we do the work? If you start to do the coding and get stuck on a concept, we will try to talk you past it, but you should not expect us to to the work that your teacher expects you to do. With that said, here is VB function (for information purposes only) that will calculate exact factorials up to a value of N equal to 31 which is a 34 digit number (it will report an approximate value in scientific notation for larger values of N). LET ME CAUTION YOU though, if you try to turn this code into your teacher as if it were your own work, I can GUARANTEE you that your teacher will know that you did not write the code as it uses techniques beginner (and even some intermediate) programmers would not know how to use.

Function BigFactorial(N As Long) As Variant
  Dim X As Long
  If N < 28 Then
    BigFactorial = CDec(1)
    For X = 1 To N
      BigFactorial = X * BigFactorial
    Next
  ElseIf N > 31 Then
    BigFactorial = CDbl(1)
    For X = 1 To N
      BigFactorial = X * BigFactorial
    Next
  Else
    BigFactorial = CDec("10888869450418352160768")
    For X = 28 To N
      BigFactorial = X * BigFactorial
    Next
    BigFactorial = BigFactorial & "000000"
  End If
End Function