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