10 N# = 27
20 P = 1
30 GOSUB 130
40 PRINT "That took";C;"steps."
50 P = 0 : A = 0 : B = 0
60 FOR M = 1 TO 99999!
70 N# = M
80 GOSUB 130
90 IF C > B THEN B = C: A = M
100 NEXT M
110 PRINT "The longest sequence is for n=";A;" and is ";B;" steps long."
120 END
130 C = 1
140 IF P = 1 THEN PRINT N#
150 IF N# < 2 THEN RETURN
160 IF N#/2 = INT(N#/2) THEN N# = N#/2 ELSE N# = 3*N# + 1
170 C = C + 1
180 GOTO 140