用VB变成，有一数列：1、1、2、3、5、8、13、21…求出这个数列的前20项之和。

Dim a,b,i As Integer
Dim c,s As Long
a=1
b=1
s=2
For i=3 To 20
c=a+b
a=b
b=c
s=s+c
Next i
Print s

a=1 '开始的数字
b=0 '增加度
c=0 '储存结果
for i=0 to 20
a=a+b
c=c+a
b=b+1
next
msgbox c

dim a(19) as integer
dim s as long
dim i as integer
a(0) = 1
a(1) = 1
s = a(0)
for i = 1 to 19
s = s + a(i)
a(i+1) = a(i) + a(i-1)
next
msgbox "结果等于" & s

Private Sub Form_Load()
Me.Show
Dim a(1 To 20) As Integer, s As Integer
a(1) = 1
For i = 1 To 20
If i = 2 Or i = 1 Then
a(i) = a(1)
Else
a(i) = a(i - 1) + a(i - 2)
End If
Print a(i) & ",";
s = s + a(i)
Next i
Print
Print s
End Sub