(c) 2006, Tomás Oliveira e Silva
 
http://www.ieeta.pt/~tos/3x+1.html 
Last update made on May 26, 2006

Records for 3n+1 sequence

s(n) is the stopping time of n

-- ----
  
n  s(n) 
-- ----
                    
2    1 
3    4 
7    7 
27   59 
703   81 
10087  105 
35655  135 
270271  164 
362343  165 
381727  173 
626331  176 
1027431  183 
1126015  224 
8088063  246 
13421671  287 
20638335  292 
26716671  298 
56924955  308 
63728127  376 
217740015  395 
1200991791  398 
1827397567  433 
2788008987  447 
12235060455  547 
898696369947  550 
2081751768559  606 
13179928405231  688 
31835572457967  712 
70665924117439  722 
739448869367967  728 
1008932249296231  886 
118303688851791519  902 
180352746940718527  966 
1236472189813512351  990 
808
2602714556700227743 1005