Sub BIF1()

For c = 0 To 4 Step 0.01

Cells(100 * c + 1, 1).Value = c

Let xold = 0.5

For n = 1 To 200

Let xnew = c * xold * (1 - xold)

If n >= 150 Then Cells(100 * c + 1, n - 148).Value =xnew

Let xold = xnew

Next n

Next c

End Sub