Time for an 2014 update…

Task/Hailstone-sequence/BASIC/hailstone-sequence-2.basic

@@ -0,0 +1,23 @@
+      seqlen% = FNhailstone(27, TRUE)
+      PRINT '"Sequence length = "; seqlen%
+      maxlen% = 0
+      FOR number% = 2 TO 100000
+        seqlen% = FNhailstone(number%, FALSE)
+        IF seqlen% > maxlen% THEN
+          maxlen% = seqlen%
+          maxnum% = number%
+        ENDIF
+      NEXT
+      PRINT "The number with the longest hailstone sequence is " ; maxnum%
+      PRINT "Its sequence length is " ; maxlen%
+      END
+
+      DEF FNhailstone(N%, S%)
+      LOCAL L%
+      IF S% THEN PRINT N%;
+      WHILE N% <> 1
+        IF N% AND 1 THEN N% = 3 * N% + 1 ELSE N% DIV= 2
+        IF S% THEN PRINT N%;
+        L% += 1
+      ENDWHILE
+      = L% + 1