求数列的通项公式

ysr

4055818759与4056818759之间的素数开头最多有公差为6469693230的9个连续素数:用时6479.16秒
合1.79小时

Private Sub Command1_Click()
Dim a, b
a = Val(Text1)
a1 = a
Q = Val(Text2)
r = Val(Text4)
t = Timer
m = Sqr(Q)
If Right(a, 1) Mod 2 = 0 Then
a = a + 1
Else
a = a
End If

Do While InStr(fenjieyinzi(Val(a)), "*") <> 0
a = a + 2
Loop

Do While a <= Q
b = a
d = fenjieyinzi(Val(b))
s = 0
s3 = ""
Do While s >= 0 And InStr(d, "*") = 0
s4 = s + 1
If s4 Mod 20 = 0 Then
s3 = s3 & "/" & b & vbCrLf
Else
s3 = s3 & "/" & b
End If
s = s + 1
s2 = s * (s + 1)
b = b + r
d = fenjieyinzi(Val(b))
Loop
If s >= 10 Then
Text3 = Text3 & s3 & vbCrLf
End If
If s > 1 Then
s5 = s5 & "/" & s
Else
s5 = s5
End If
Print s5
a = a + 2
s2 = 0
Loop
s6 = Mid(s5, 2)
     s7 = max(Trim(s6))
Combo1 = a1 & "与" & Q & "之间的素数开头最多有公差为" & r & "的" & s7 & "个连续素数:用时" & Timer - t & "秒 " & vbCrLf & Text3


     

End Sub

Private Sub Command2_Click()
Text1 = ""
Text2 = ""
Text3 = ""
Text4 = ""
Combo1 = ""
Form1.Cls
End Sub
Private Function max(ByVal lists As String) As String
Dim temp As Long
Dim a() As String
a = Split(lists, "/")
Dim b As Long

For b = 0 To UBound(a)
If temp < a(b) Then temp = a(b)
Next
max = temp
End Function

Private Function fenjieyinzi(sa As String) As String
Dim x, a, b
x = sa
b = Int(Sqr(Val(x)))
If x = 3 Or x = 2 Then
a = True
Else
If Val(x / 2) - Int(Val(x / 2)) = 0 Then
a = False
Else

For i = 3 To b Step 2
If Val(x / i) - Int(Val(x / i)) = 0 Then
a = False
Exit For

Else: a = True

End If
Next
End If
End If
If a = True Then
fenjieyinzi = "这是个素数"
Else
fenjieyinzi = "2*2"
End If

End Function

ysr

4055718759与4055719759之间的素数开头最多有公差为6469693230的3个连续素数:用时2.203125秒
这个程序慢，咋改也不行？代码：

Private Function fenjieyinzi(sa As Double) As String
'改进了一下
Dim x, a, b
x = Val(sa)
b = Sqr(Val(x))
If x = 3 Or x = 2 Then
a = True: fenjieyinzi = "这是个素数"
Else
If Right(x, 1) Mod 2 = 0 Then
a = False: fenjieyinzi = "2*2"
Else
i = 3
Do While i <= b And InStr(Val(x / i), ".") > 0
i = i + 2
Loop
If InStr(Val(x / i), ".") = 0 Then
a = False: fenjieyinzi = "2*2"

Else: a = True: fenjieyinzi = "这是个素数"

End If


End If
End If

End Function

ysr

4055718759与4055719759之间的素数开头最多有公差为6469693230的3个连续素数:用时0.734375秒
还是这个快，不知道咋回事：

Private Sub Command1_Click()
Dim a, b
a = Val(Text1)
a1 = a
Q = Val(Text2)
r = Val(Text4)
t = Timer
m = Sqr(Q)
If Right(a, 1) Mod 2 = 0 Then
a = a + 1
Else
a = a
End If

Do While InStr(fenjieyinzi(Val(a)), "*") <> 0
a = a + 2
Loop

Do While a <= Q
b = a
d = fenjieyinzi(Val(b))
s = 0
s3 = ""
Do While s >= 0 And InStr(d, "*") = 0
s4 = s + 1
If s4 Mod 20 = 0 Then
s3 = s3 & "/" & b & vbCrLf
Else
s3 = s3 & "/" & b
End If
s = s + 1
s2 = s * (s + 1)
b = b + r
d = fenjieyinzi(Val(b))
Loop
If s >= 10 Then
Text3 = Text3 & s3 & vbCrLf
End If
If s > 1 Then
s5 = s5 & "/" & s
Else
s5 = s5
End If
Print s5
a = a + 2
s2 = 0
Loop
s6 = Mid(s5, 2)
     s7 = max(Trim(s6))
Combo1 = a1 & "与" & Q & "之间的素数开头最多有公差为" & r & "的" & s7 & "个连续素数:用时" & Timer - t & "秒 " & vbCrLf & Text3

     

End Sub

Private Sub Command2_Click()
Text1 = ""
Text2 = ""
Text3 = ""
Text4 = ""
Combo1 = ""
Form1.Cls
End Sub
Private Function max(ByVal lists As String) As String
Dim temp As Long
Dim a() As String
a = Split(lists, "/")
Dim b As Long

For b = 0 To UBound(a)
If temp < a(b) Then temp = a(b)
Next
max = temp
End Function

Private Function fenjieyinzi(sa As String) As String
Dim x, a, b, k As String
a = Val(sa)

x = 3
If a <= 1 Or a > Int(a) Then
If a = 1 Then
fenjieyinzi = "它既不是质数，也不是合数"

Else
MsgBox "error"
End If
  
Else

Do While a / 2 = Int(a / 2) And a >= 4
  
If b = 0 Then
fenjieyinzi = fenjieyinzi & "2"
b = 1
Else
fenjieyinzi = fenjieyinzi & "*2"
End If
a = a / 2
k = a
  
Loop

Do While a > 1
Do While x <= Sqr(a)
Do While a / x = Int(a / x) And a >= x * x
  
If b = 0 Then
fenjieyinzi = fenjieyinzi & x
b = 1
Else
fenjieyinzi = fenjieyinzi & "*" & x
End If
a = a / x
Loop
  
x = x + 2
Loop
  
k = a
a = 1
Loop
  
If b = 1 Then
fenjieyinzi = fenjieyinzi & "*" & k
Else
fenjieyinzi = "这是一个质数"
End If

End If

End Function

ysr

4170958869   +   123040110 =4,293,998,979
用那个快速程序算一下这个：从4170958869 到4,293,998,979试试，公差6469693230

ysr

4294998979与4295098979之间的素数开头最多有公差为6469693230的8个连续素数:用时101.2656秒
这个就是快速程序算的比慢的程序快了大约5倍

ysr

4295098979+123040110 =4295098979
用这个程序从4295098979算到4418139089，公差6469693230

ysr

4293998979与4294998979之间的素数开头最多有公差为6469693230的9个连续素数:用时2190.59秒
合0.6小时

ysr

4418139089与4421139089之间的素数开头最多有公差为6469693230的9个连续素数:用时12502.54秒
合3.47小时

ysr

刚才单位停电了，程序都白了，还得重新开始，再把前面的重新复制一下吧，分段计算
4047918759+123,040,110=4,170,958,869
4047918759~4170958869，公差6469693230

ysr

4170958869+123,040,110=4293998979
4,293,998,979+123,040,110=4417039089
4,417,039,089+123,040,110=4540079199

快速程序的运行时间：

整数个数                      运行时间
1000内                         1秒
10000                          100
100000                        1000         合0.27777小时
1000000                      10000       合2.7777小时