3x+1 Class records calculation progress map
Status of the 3x+1 class record progress as of: Nov 22, 2021.
Intervals are indicated in units of 1,000,000,000,000 (1 E+12 or 1 trillion numbers).
Calculation of a single block of 10,000 units takes approximately 5-10 days on an NVIDIA graphics processor.

All class records found so far can be viewed on the class records page.
This project can only run because of many cooperating contributors.
If you would like to contribute one or more blocks please go to the search page.
Note : the 3x+1 problem is just one of many distributed projects on the internet.
Trajectory of 63,728,127
Progress history
November 15 2021 : All blocks up to 10090,000 completed. Delay record 2426 and two more class records confirmed.
September 29 2021 : Possible new Delay record (Delay 2426) found by Kevin.
September 14 2021 : All blocks up to 9460,000 completed. Two more class records confirmed.
August 30 2021 : All blocks up to 9000,000 completed. Five more class records confirmed.
August 6 2021 : All blocks up to 8300,000 completed. One more class record confirmed.
July 12 2021 : All blocks up to 8000,000 completed. Four more class records confirmed.
June 25 2021 : All blocks up to 7260,000 completed. Four more class records confirmed.
May 19 2021 : All blocks up to 6640,000 completed. Two Delay records (2363,2389) and 12 class records confirmed.
April 26 2021 : Possible new Delay record (Delay 2389) found by Kevin.
February 18 2021 : Possible new Delay record (Delay 2363) found by Kevin.
February 1 2021 : All blocks up to 4850,000 completed. New Delay record (2337) found by Volkmar.
January 30 2021 : All blocks up to 4700,000 completed. One more class record confirmed.
January 25 2021 : All blocks up to 4550,000 completed. Seven class records confirmed.
December 30 2020 : All blocks up to 3940,000 completed. Three class records confirmed. All class records below 2200 known.
December 21 2020 : All blocks up to 3720,000 completed. Delay record 2334 and seven more class records confirmed
December 15 2020 : Possible new Delay record (Delay 2334) found by Kevin.
November 18 2020 : All blocks up to 2900,000 completed. Delay record 2331 and ten more class records confirmed
October 2 2020 : All blocks up to 2470,000 completed. Two more class records confirmed
September 18 2020 : All blocks up to 2300,000 completed. Six more class records confirmed
September 6 2020 : All blocks up to 2100,000 completed. Five more class records confirmed
September 2 2020 : All blocks up to 2000,000 completed. Fifteen more class records confirmed
August 30 2020 : All blocks up to 1620,000 completed. Eight more class records confirmed
July 20 2020 : All blocks up to 1360,000 completed. Delay record 2330 and seven more class records confirmed
July 5 2020 : All blocks up to 1300,000 completed. Two Delay records (2283,2286) and 35 class records confirmed
June 30 2020 : Possible new Delay record (Delay 2330) found by Eric.
June 28 2020 : Possible new Delay record (Delay 2286) found by Kevin.
May 30 2020 : Possible new Delay record (Delay 2283) found by Kevin.
Show/Hide earlier milestones
May 2020 : All blocks up to 820,000 completed. Sixteen class record confirmed. All class records below 2100 known.
March 2020 : All blocks up to 698,000 completed. Twelve more class records confirmed.
December 2019 : All blocks up to 602,000 completed. Nine class records confirmed.
September 2019 : All blocks up to 561,200 completed. Delay record 2277 and ten more class record confirmed.
May 2019 : All blocks up to 500,000 completed. Delay record 2264 and eight more class records confirmed.
March 2019 : All blocks up to 455,200 completed. Lowest missing class record (2070) and four others confirmed.
December 2018 : All blocks up to 387,000 completed. Delay record 2261 and nine more class records confirmed.
October 2018 : All blocks up to 366,400 completed. Six more class records confirmed.
June 2018 : All blocks up to 346,000 completed. Three more class records confirmed.
December 2017 : All blocks up to 326,500 completed. Five more class records confirmed.
May 2017 : All blocks up to 305,400 completed. 258 reached. Two more class record confirmed.
October 2016 : All blocks up to 280,000 completed. Delay record 2258 and two more class records confirmed.
March 2016 : All blocks up to 275,200 completed. Four more class records confirmed.
March 19 2016 : Possible new Delay Record (Delay 2258) found by Lutz.
December 2015 : All blocks up to 263,350 completed. Four more class records confirmed. 2100 class records known.
July 2015 : All blocks up to 245,500 completed. Five more class records confirmed.
December 2014 : All blocks up to 222,280 completed. Three more class records confirmed.
November 2014 : All blocks up to 213,800 completed. Delay record 2255 and two more class records confirmed.
May 2014 : All blocks up to 203,920 completed. Three class records confirmed.
February 2014 : All blocks up to 194,060 completed. Five class records confirmed. All class records up to 2050 known.
November 2013 : All blocks up to 184,000 completed. Three more class records confirmed
June 2013 : All blocks up to 166,700 completed. Two more class records confirmed.
April 2013 : All blocks up to 165,200 completed. One more class record confirmed.
February 2013 : All blocks up to 160,740 completed. Six more class records confirmed.
November 2012 : All blocks up to 148,800 completed. Five more class records confirmed
May 2012 : All blocks up to 132,360 completed. Five class records confirmed.
January 2012 : All blocks up to 121,500 completed. Final missing class record below 2000 found.
December 2011 : All blocks up to 120,200 completed. One class record confirmed.
October 2011 : All blocks up to 117,000 completed. Three more class record confirmed.
July 2011 : All blocks up to 107,500 completed. Delay record 2254 and three class records confirmed.
April 2011 : All blocks up to 97,080 completed. Delay Record 2091 and two other class records confirmed.
November 2010 : All blocks up to 91,880 completed. Three class records confirmed.
August 2010 : All blocks up to 90,000 completed. Four more class records confirmed.
February 2010 : All blocks up to 82,700 completed. Two class records confirmed.
June 2009 : All blocks up to 76,160 completed. The lowest missing CR (1964) and one other confirmed.
April 2009 : All blocks up to 72,520 completed, passing 256. Three class records confirmed.
February 2009 : All blocks up to 71,020 completed. One more class record confirmed.
December 2008 : All blocks up to 69,740 completed. The lowest missing CR (1951) and two more confirmed.
November 2008 : All blocks up to 67,500 completed. Class record 2000 finally confirmed.
October 2008 : All blocks up to 66,380 completed. Four more class records confirmed.
May 2008 : All blocks up to 61,160 completed. The lowest missing CR (1925) and three others confirmed.
December 2007 : All blocks up to 58,600 completed. Four class records confirmed.
April 2007 : All blocks up to 54,540 completed. Five more class records confirmed.
October 2006 : All blocks up to 50,000 completed. Delay Record 2090 and five class records confirmed.
November 2005 : All blocks up to 46,100 completed. Double of Record 2045 confirmed as Delay Record 2046.
August 2005 : All blocks up to 45,040 completed. Five class records confirmed.
May 2005 : Delay Record of 2090 found at ±46,785 E+12 by Eric
February 2005 : All blocks up to 42,060 completed. Three more class record confirmed.
November 2004 : All blocks up to 40,000 completed. Four class records confirmed.
August 2004 : All blocks up to 37,500 completed. Another four class records confirmed.
May 2004 : All blocks up to 36,120 completed. Seven class records confirmed.
January 2004 : All blocks up to 31,960 completed. Five further class records confirmed.
November 2003 : All blocks up to 29,840 completed. One more class record confirmed.
August 2003 : All blocks up to 29,240 completed. Another fifteen class records confirmed.
April 2003 : All blocks up to 23,100 completed. Delay record 2045 and seven class records confirmed.
December 2002 : All blocks up to 20,100 completed. All class records below 1900 known.
November 2002 : All blocks up to 20,000 completed. Delay record 2042 and fourteen class records confirmed.
November 2002 : Delay Record of 2045 found at ±22,702 E+12 by Kevin
July 2002 : All blocks up to 16,460 completed. Delay record 2039 and fifteen class records confirmed.
April 2002 : All blocks up to 12,720 completed. Another fourteen class records confirmed.
March 2002 : Delay Record of 2042 found at ±17,026 E+12 by Michael
February 2002 : All blocks up to 9340 completed. Two more class records confirmed.
December 2001 : Delay Record of 2039 found at ±12,770 E+12 by Billy
November 2001 : All blocks up to 9020 completed. One Delay record and ten class records confirmed.
September 2001 : All blocks up to 6800 completed. Three Delay records and fourteen class records confirmed. 
August 2001 : All blocks up to 3600 completed. Two Delay records and five class records confirmed
June 2001 : Delay Record of 1958 found at ±7579 E+12 by Kevin
May 2001 : Delay Record of 1919 found at ±6482 E+12 by Kevin
April 2001 : Delay Record of 1916 found at ±4861 E+12 by Kevin
March 2001 : Delay Record of 1903 found at ±4320 E+12 by Kevin
March 2001 : Delay Record of 1895 found at ±3586 E+12 by Eric
March 2001 : Delay Record of 1874 found at ±2978 E+12 by Kevin
February 2001 : All blocks up to 2620 completed. Three class records confirmed.
January 2001 : New Class and Delay Record of 1871 found at 2234,047405,400065.

Range 2000-20000
completed (view)
Range 20000-40000
completed (view)
Range 40000-60000
completed (view)
Range 60000-80000
completed (view)
Range 80000-100000
completed (view)
Range 100000-120000
completed (view)
Range 120000-140000
completed (view)
Range 140000-160000
completed (view)
Range 160000-180000
completed (view)
Range 180000-200000
completed (view)
Range 200000-300000
completed (view)
Range 300000-400000
completed (view)
Range 400000-500000
completed (view)
Range 500000-600000
completed (view)
Range 600000-700000
completed (view)
Range 700000-800000
completed (view)
Range 800000-900000
completed (view)
Range 900000-1000000
completed (view)
Range 1000000-2000000
completed (view)
Range 2000000-3000000
completed (view)
Range 3000000-4000000
completed (view)
Range 4000000-5000000
completed (view)
Range 5000000-10000000
completed (view)
 
Not yet assigned Assigned,
not yet started
Assigned,
in progress
Entire interval
completed
Interval completed
class record found
10000000-10000
Luiz
10010000-20000
Luiz
10020000-30000
Eric
10030000-40000
Eric
10040000-50000
Lutz
10050000-60000
Lutz
10060000-70000
Daniel
10070000-80000
Daniel
10080000-90000
Eric
10090000-00000
Joel
10100000-10000
Volkmar
10110000-20000
Volkmar
10120000-30000
Volkmar
10130000-40000
Volkmar
10140000-50000
Volkmar
10150000-60000
Volkmar
10160000-70000
Volkmar
10170000-80000
Volkmar
10180000-90000
Volkmar
10190000-00000
Volkmar
10200000-10000
Mark
10210000-20000
Daniel
10220000-30000
Daniel
10230000-40000
Kirill
10240000-50000
Lutz
10250000-60000
Lutz
10260000-70000
Eric
10270000-80000
Eric
10280000-90000
Eric
10290000-00000
Eric
10300000-10000
Kevin
10310000-20000
Kevin
10320000-30000
Kevin
10330000-40000
Kevin
10340000-50000
Kevin
10350000-60000
Kevin
10360000-70000
Kevin
10370000-80000
Kevin
10380000-90000
Kevin
10390000-00000
Kevin
10400000-10000
Kevin
10410000-20000
Kevin
10420000-30000
Kevin
10430000-40000
Kevin
10440000-50000
Kevin
10450000-60000
Kevin
10460000-70000
Kevin
10470000-80000
Kevin
10480000-90000
Kevin
10490000-00000
Kevin
10500000-10000
Kevin
10510000-20000
Kevin
10520000-30000
Kevin
10530000-40000
Kevin
10540000-50000
Kevin
10550000-60000
Kevin
10560000-70000
Kevin
10570000-80000
Kevin
10580000-90000
Kevin
10590000-00000
Kevin
10600000-10000
Kevin
10610000-20000
Kevin
10620000-30000
Kevin
10630000-40000
Kevin
10640000-50000
Kevin
10650000-60000
Kevin
10660000-70000
Kevin
10670000-80000
Kevin
10680000-90000
Kevin
10690000-00000
Kevin
10700000-10000
Volkmar
10710000-20000
Volkmar
10720000-30000
Volkmar
10730000-40000
Volkmar
10740000-50000
Volkmar
10750000-60000
Volkmar
10760000-70000
Volkmar
10770000-80000
Volkmar
10780000-90000
Volkmar
10790000-00000
Volkmar
10800000-10000
Daniel
10810000-20000
Daniel
10820000-30000
Mehmet
10830000-40000
Kirill
10840000-50000
Lutz
10850000-60000
Lutz
10860000-70000
Luiz
10870000-80000
Luiz
10880000-90000
Daniel
10890000-00000
Daniel
10900000-10000
Kevin
10910000-20000
Kevin
10920000-30000
Kevin
10930000-40000
Kevin
10940000-50000
Kevin
10950000-60000
Kevin
10960000-70000
Kevin
10970000-80000
Kevin
10980000-90000
Kevin
10990000-00000
Kevin
11000000-10000
Kevin
11010000-20000
Kevin
11020000-30000
Kevin
11030000-40000
Kevin
11040000-50000
Kevin
11050000-60000
Kevin
11060000-70000
Kevin
11070000-80000
Kevin
11080000-90000
Kevin
11090000-00000
Kevin
11100000-10000
Kevin
11110000-20000
Kevin
11120000-30000
Kevin
11130000-40000
Kevin
11140000-50000
Kevin
11150000-60000
Kevin
11160000-70000
Kevin
11170000-80000
Kevin
11180000-90000
Kevin
11190000-00000
Kevin
11200000-10000
Kevin
11210000-20000
Kevin
11220000-30000
Kevin
11230000-40000
Kevin
11240000-50000
Kevin
11250000-60000
Kevin
11260000-70000
Kevin
11270000-80000
Kevin
11280000-90000
Kevin
11290000-00000
Kevin
11300000-10000
Volkmar
11310000-20000
Volkmar
11320000-30000
Volkmar
11330000-40000
Volkmar
11340000-50000
Volkmar
11350000-60000
Volkmar
11360000-70000
Volkmar
11370000-80000
Volkmar
11380000-90000
Volkmar
11390000-00000
Volkmar
11400000-10000
Lutz
11410000-20000
Lutz
11420000-30000
Wenjie
11430000-40000
Wenjie
11440000-50000
11450000-60000
11460000-70000
11470000-80000
11480000-90000
11490000-00000
Contributions by
EricEric Roosendaal, Netherlands (author) LutzLutz Nebe, Germany
KevinKevin Hebb, Alberta, Canada WenjieFang Wenjie, China
LuizLuiz Antonio Souza, Brazil DanielDaniel Podobinski
VolkmarVolkmar Schmidt JoelJoel Vogt
MarkMark Kortink KirillKirill Frolov
MehmetMehmet Kaçmaz   

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