EnableExplicit

Procedure.i SumProperDivisors(Number)
  If Number < 2 : ProcedureReturn 0 : EndIf
  Protected i, sum = 0
  For i = 1 To Number / 2
    If Number % i = 0
      sum + i
    EndIf
  Next
  ProcedureReturn sum
EndProcedure

Define n, f
Define Dim sum(19999)

If OpenConsole()
  For n = 1 To 19999
    sum(n) = SumProperDivisors(n)
  Next
  PrintN("The pairs of amicable numbers below 20,000 are : ")
  PrintN("")
  For n = 1 To 19998
    f = sum(n)
    If f <= n Or f < 1 Or f > 19999 : Continue : EndIf
    If f = sum(n) And n = sum(f)
      PrintN(RSet(Str(n),5) + " and " + RSet(Str(sum(n)), 5))
    EndIf
  Next
  PrintN("")
  PrintN("Press any key to close the console")
  Repeat: Delay(10) : Until Inkey() <> ""
  CloseConsole()
EndIf