10 DEFINT A-Z
20 N=3
30 S=N: T=0
40 X=S: S=0
50 FOR I=1 TO X-1
60 A=X: B=I
70 IF B>0 THEN C=A: A=B: B=C MOD B: GOTO 70
80 IF A=1 THEN S=S+1
90 NEXT
100 T=T+S
110 IF S>1 GOTO 40
120 IF T=N THEN PRINT N,: Z=Z+1
130 N=N+2
140 IF Z<20 GOTO 30