Вычислить сумму, используя циклы - VB

'найти сумму 1+ A + A2 + A3 + ... + AN
Private Sub Command1_Click()
Dim i As Integer, sum As Integer
Dim A As Single, n As Integer
A = InputBox("A = ", , 2): n = InputBox("N = ", , 10)
 
For i = 0 To n
  sum = sum + A ^ i
Next i
 
MsgBox sum, vbInformation
End Sub