Question

已知A1=0,A2=1,A3=2,A4=A1+2*A2+A3;A5=A2+2*A3+A4...求A23

Private Sub Form_Click()
Dim a As Long, b As Long, c As Long, d As Long, e As Long, f As Long, g As Long
a = 0: b = 1: c = 2
For e = 1 To 20
For f = 1 To 20
For g = 1 To 20
d = a + 2 * b + c
Next g
Next f
Next e
Print d
End Sub
------------------------调试，显示结果为4，显然不可能，我错在哪咯？----------------------------------------------------------

Answer 1

Private Sub Command1_Click()
Dim a As Long, b As Long, c As Long, d As Long
a = 0: b = 1: c = 2
For i = 4 To 23
d = a + 2 * b + c
a = b
b = c
c = d
Next i
Print c
End Sub

Answer 2

4 A1=0,A2=1,A3=2,A4=A1+2*A2+A3;A5=A2+2*A3+A4...求A23

Answer 3

1

Answer 4

1111111111111111111111111111

Answer 5

,本来就是4的嘛,
一下子想不出关系来,只能先这样算了.

呵呵,楼上的已经做好了啊,没看到呢

Private Sub Command1_Click()
Dim a(23) As Long

a(1) = 0
a(2) = 1
a(3) = 2
For i = 4 To 23
a(i) = a(i - 3) + 2 * a(i - 2) + a(i - 1)

Next
Print a(23)

End Sub