10 DEFINT A-Z: DIM B$(2): B$(0)="No": B$(1)="Yes"
20 PRINT " N  Totient  Prime"
30 FOR N=1 TO 25
40 GOSUB 200
50 P=-(T=N-1)
60 C=C+P
70 PRINT USING "##  #######  \   \";N;T;B$(P)
80 NEXT N
90 F$="Number of primes up to ######: ####"
100 PRINT USING F$;25;C
110 FOR N=26 TO 10000
120 GOSUB 200
130 C=C-(T=N-1)
140 IF N=100 OR N=1000 OR N=10000 THEN PRINT USING F$;N;C
150 NEXT N
160 END
200 REM T = TOTIENT(N)
210 T=N: Z=N
220 I=2: GOSUB 270
230 I=3
240 IF I*I<=Z THEN GOSUB 270: I=I+2: GOTO 240
250 IF Z>1 THEN T=T-T\Z
260 RETURN
270 IF Z MOD I<>0 THEN RETURN
280 IF Z MOD I=0 THEN Z = Z\I: GOTO 280
290 T = T-T\I
300 RETURN