100 PRINT : PRINT "HAILSTONE SEQUENCE FOR N = 27:"
110 N=27 : SHOW=1
120 GOSUB 1000
130 PRINT X"ELEMENTS"
140 PRINT : PRINT "FINDING N WITH THE LONGEST HAILSTONE SEQUENCE"
150 SHOW=0
160 T0 = TI
170 FOR N=2 TO 100000
180 : GOSUB 1000
190 : IF X>MAX THEN MAX=X : NMAX = N
200 : REM' PRINT N,X,MAX
210 NEXT
230 PRINT "LONGEST HAILSTONE SEQUENCE STARTS WITH "NMAX"."
240 PRINT "IT HAS"MAX"ELEMENTS"
260 END
1000 REM '*** HAILSTONE SEQUENCE SUBROUTINE ***
1010 X = 0 : S = N
1020 IF SHOW THEN PRINT S,
1030 X = X+1
1040 IF S=1 THEN RETURN
1050 IF INT(S/2)=S/2 THEN S = S/2 : GOTO 1020
1060 S = 3*S+1
1070 GOTO 1020