应用程序定义或对象定义的错误运行时错误1004

Question

当我运行此代码时，我得到“运行时错误1004”应用程序定义或对象定义错误。我的搜索没有产生任何结果。

Public Sub problem2()

Dim i As Integer
Dim num(1 To 40) As Long
Dim sum As Long

num(1) = 1
num(2) = 2
Cells(1, 2).Value = num(1)
Cells(2, 2).Value = num(2)
For i = 3 To 40
    num(i) = num(i - 1) + num(i - 2)
    Cells(i, 2).Value = num(i)
Next i

i = 1
sum = 0
Do While num(i) < 4000000
    If Cells(i, 2).Value Mod 2 = 0 Then sum = sum + num(i)
    i = i + 1
Loop

Range(A1).Value = sum
End Sub