1+2+5+10+17+26+37+…

求前二十项的和。对吗？

Private Sub Command1_Click() Dim a(20) As Integer a(1) = 1 For i = 2 To 20 a(i) = a(i - 1) + 2 * (i - 1) - 1 Next

Print a(20)

End Sub

Private Sub Command1_Click() Dim a(20) As Integer Dim i As Integer Dim sum As Integer sum = 1 a(1) = 1 For i = 2 To 20 a(i) = a(i - 1) + 2 * (i - 1) - 1 sum = sum + a(i) Print sum Next

End Sub

都不对啊！你们a(i)表达式都不对啊！
Private Sub Command1_Click()
Dim a(20) As Integer
Dim i As Integer
Dim sum As Integer
sum = 1
a(1) = 1
For i = 2 To 20
a(i) = a(i - 1) + 2 * (i - 1) - 1

sum = sum + a(i)
Print sum
Next

End Sub

Dim I As Integer, K As Integer

K = 0
For I = 0 To 19 '刚刚错打成3了不好意思
K = K + I ^ 2 + 1
Next
Print K

[此贴子已经被作者于2007-4-10 17:03:28编辑过]