100 CLS
110 PRINT "The first 20 perfect totient numbers:"
120 n = 3
130 s = n : t = 0
140 x = s : s = 0
150 FOR i = 1 TO x-1
160  a = x : b = i
170  IF b > 0 THEN c = a : a = b : b = c MOD b : GOTO 170
180  IF a = 1 THEN s = s+1
190 NEXT i
200 t = t+s
210 IF s > 1 THEN GOTO 140
220 IF t = n THEN PRINT n;" "; : z = z+1
230 n = n+2
240 IF z < 20 THEN GOTO 130
250 END