10 REM Moebius function
20 FOR T = 0 TO 9
30 FOR U = 1 TO 10
40 LET N = 10*T+U
50 GOSUB 110
60 PRINT M;" ";
70 NEXT U
80 PRINT
90 NEXT T
100 END

110 LET M = 1
120 IF N = 1 THEN 230
130 LET F = 2
140 LET F2 = F*F
150 IF INT(N/F2)*F2 <> N THEN 180
160 LET M = 0
170 GOTO 230
180 IF INT(N/F)*F <> N THEN 210
190 LET M = -M
200 LET N = N/F
210 LET F = F+1
220 IF F <= N THEN 140
230 RETURN