' Moebius function
DECLARE FUNCTION Moebius% (N%)
FOR T% = 0 TO 9
  FOR U% = 1 TO 10
    PRINT USING "##  "; Moebius%(10 * T% + U%);
  NEXT U%
  PRINT
NEXT T%
END

FUNCTION Moebius% (N%)
  M% = 1
  IF N% <> 1 THEN
    F% = 2
    DO
      IF (N% MOD (F% * F%)) = 0 THEN
        M% = 0
      ELSE
        IF N% MOD F% = 0 THEN
          M% = -M%
          N% = N% \ F%
        END IF
        F% = F% + 1
      END IF
    LOOP WHILE (F% <= N%) AND (M% <> 0)
  END IF
  Moebius% = M%
END FUNCTION