' version 04-10-2016
' compile with: fbc -s console
' replaced the function with 2 FOR NEXT loops

#Define max 20000      ' test for pairs below max
#Define max_1 max -1

Dim As String u_str = String(Len(Str(max))+1,"#")
Dim As UInteger n, f
Dim Shared As UInteger sum(max_1)

For n = 2 To max_1
  sum(n) = 1
Next

For n = 2 To max_1 \ 2
  For f  = n * 2 To max_1 Step n
    sum(f) += n
  Next
Next

Print
Print Using " The pairs of amicable numbers below" & u_str & ", are :"; max
Print

For n = 1 To max_1 -1
  f = Sum(n)
  If f <= n OrElse f > max Then Continue For
  If f = sum(n) AndAlso n = sum(f) Then
    Print Using u_str & " and" & u_str ; n; f
  End If
Next

' empty keyboard buffer
While Inkey <> "" : Wend
Print : Print : Print " Hit any key to end program"
Sleep
End