使用递归

有1例 1000 每增加1例增加500 

Public Function js(a As Integer) As Integer
Dim i, j, s
j = 500
s = 1000
If a <= 1 Then
js = a * s
Else
js = js(a - 1) + s + j * (a - 1)
End If

End Function

 用菊子曰写博客，就是爽！