用VB多重循环编写程序,求3!+6!+9！

不清楚什么是"多重循环"
是
for
for
next
next
还是
for
next
for
next
二个都能写,我一个给你写一个啊
Private Sub CommandButton1_Click()
sum = 0
a = 1
For i = 1 To 3
a = a * i
Next
sum = a + sum
a = 1
For i = 1 To 6
a = a * i
Next
sum = a + sum
a = 1
For i = 1 To 9
a = a * i
Next
sum = a + sum
MsgBox (sum)
End Sub

运行正确
Private Sub Command1_Click()
Dim i, j, s
s = 1
For i = 3 To 9 Step 3
For j = 1 To i
s = s * j
Next j
Next i
Print s
End Sub

多重循环？？？？？？？？？是递归吧