3x+1 Class records calculation progress map
Status of the 3x+1 class record progress as of: Jan 7, 2022. 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.
Progress history December 26 2021 : All blocks up to 10820,000 completed. Three more class records confirmed. 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 Wentao
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 Eric	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 Eric	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 Daniel	11450000-60000 Daniel	11460000-70000 Wentao	11470000-80000 Wentao	11480000-90000 Wentao	11490000-00000 Wentao
11500000-10000 Volkmar	11510000-20000 Volkmar	11520000-30000 Volkmar	11530000-40000 Volkmar	11540000-50000 Volkmar	11550000-60000 Volkmar	11560000-70000 Volkmar	11570000-80000 Volkmar	11580000-90000 Volkmar	11590000-00000 Volkmar
11600000-10000 Kevin	11610000-20000 Kevin	11620000-30000 Kevin	11630000-40000 Kevin	11640000-50000 Kevin	11650000-60000 Kevin	11660000-70000 Kevin	11670000-80000 Kevin	11680000-90000 Kevin	11690000-00000 Kevin
11700000-10000 Kevin	11710000-20000 Kevin	11720000-30000 Kevin	11730000-40000 Kevin	11740000-50000 Kevin	11750000-60000 Kevin	11760000-70000 Kevin	11770000-80000 Kevin	11780000-90000 Kevin	11790000-00000 Kevin
11800000-10000 Kevin	11810000-20000 Kevin	11820000-30000 Kevin	11830000-40000 Kevin	11840000-50000 Kevin	11850000-60000 Kevin	11860000-70000 Kevin	11870000-80000 Kevin	11880000-90000 Kevin	11890000-00000 Kevin
11900000-10000 Kevin	11910000-20000 Kevin	11920000-30000 Kevin	11930000-40000 Kevin	11940000-50000 Kevin	11950000-60000 Kevin	11960000-70000 Kevin	11970000-80000 Kevin	11980000-90000 Kevin	11990000-00000 Kevin
12000000-10000 Wentao	12010000-20000 Wentao	12020000-30000 Wentao	12030000-40000 Lutz	12040000-50000 Lutz	12050000-60000 Eric	12060000-70000 Andrea	12070000-80000 Eric	12080000-90000 Wenjie	12090000-00000 Wenjie
12100000-10000 Kevin	12110000-20000 Kevin	12120000-30000 Kevin	12130000-40000 Kevin	12140000-50000 Kevin	12150000-60000 Kevin	12160000-70000 Kevin	12170000-80000 Kevin	12180000-90000 Kevin	12190000-00000 Kevin
12200000-10000 Kevin	12210000-20000 Kevin	12220000-30000 Kevin	12230000-40000 Kevin	12240000-50000 Kevin	12250000-60000 Kevin	12260000-70000 Kevin	12270000-80000 Kevin	12280000-90000 Kevin	12290000-00000 Kevin
12300000-10000 Kevin	12310000-20000 Kevin	12320000-30000 Kevin	12330000-40000 Kevin	12340000-50000 Kevin	12350000-60000 Kevin	12360000-70000 Kevin	12370000-80000 Kevin	12380000-90000 Kevin	12390000-00000 Kevin
12400000-10000 Kevin	12410000-20000 Kevin	12420000-30000 Kevin	12430000-40000 Kevin	12440000-50000 Kevin	12450000-60000 Kevin	12460000-70000 Kevin	12470000-80000 Kevin	12480000-90000 Kevin	12490000-00000 Kevin
12500000-10000 Wentao	12510000-20000 Wentao	12520000-30000 Wentao	12530000-40000 Luiz	12540000-50000 Luiz	12550000-60000 Daniel	12560000-70000 Daniel	12570000-80000	12580000-90000	12590000-00000
12600000-10000 Volkmar	12610000-20000 Volkmar	12620000-30000 Volkmar	12630000-40000 Volkmar	12640000-50000 Volkmar	12650000-60000 Volkmar	12660000-70000 Volkmar	12670000-80000 Volkmar	12680000-90000 Volkmar	12690000-00000 Volkmar
Contributions by Eric Eric Roosendaal, Netherlands (author) Lutz Lutz Nebe, Germany Kevin Kevin Hebb, Alberta, Canada Wenjie Fang Wenjie, China Luiz Luiz Antonio Souza, Brazil Daniel Daniel Podobinski Volkmar Volkmar Schmidt Kirill Kirill Frolov Mehmet Mehmet Kaçmaz Wentao Wentao Huang Andrea Andrea, Italy

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