3x+1 Class records calculation progress map
Status of the 3x+1 class record progress as of: Jun 17, 2021. Intervals are indicated in blocks of 100,000,000,000,000 (100 E+12 or 100 trillion numbers). Calculation of a single block 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 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)
Not yet assigned		Assigned, not yet started		Assigned, in progress		Entire interval completed		Interval completed class record found
5000000-10000 Kevin	5010000-20000 Kevin	5020000-30000 Kevin	5030000-40000 Kevin	5040000-50000 Kevin	5050000-60000 Kevin	5060000-70000 Kevin	5070000-80000 Kevin	5080000-90000 Kevin	5090000-00000 Kevin
5100000-10000 Kevin	5110000-20000 Kevin	5120000-30000 Kevin	5130000-40000 Kevin	5140000-50000 Kevin	5150000-60000 Kevin	5160000-70000 Kevin	5170000-80000 Kevin	5180000-90000 Kevin	5190000-00000 Kevin
5200000-10000 Kevin	5210000-20000 Kevin	5220000-30000 Kevin	5230000-40000 Kevin	5240000-50000 Kevin	5250000-60000 Kevin	5260000-70000 Kevin	5270000-80000 Kevin	5280000-90000 Kevin	5290000-00000 Kevin
5300000-10000 Volkmar	5310000-20000 Volkmar	5320000-30000 Volkmar	5330000-40000 Volkmar	5340000-50000 Volkmar	5350000-60000 Volkmar	5360000-70000 Volkmar	5370000-80000 Volkmar	5380000-90000 Volkmar	5390000-00000 Volkmar
5400000-10000 Volkmar	5410000-20000 Volkmar	5420000-30000 Volkmar	5430000-40000 Volkmar	5440000-50000 Volkmar	5450000-60000 Volkmar	5460000-70000 Volkmar	5470000-80000 Volkmar	5480000-90000 Volkmar	5490000-00000 Volkmar
5500000-10000 Kevin	5510000-20000 Kevin	5520000-30000 Kevin	5530000-40000 Kevin	5540000-50000 Kevin	5550000-60000 Kevin	5560000-70000 Kevin	5570000-80000 Kevin	5580000-90000 Kevin	5590000-00000 Kevin
5600000-10000 Kevin	5610000-20000 Kevin	5620000-30000 Kevin	5630000-40000 Kevin	5640000-50000 Kevin	5650000-60000 Kevin	5660000-70000 Kevin	5670000-80000 Kevin	5680000-90000 Kevin	5690000-00000 Kevin
5700000-10000 Kevin	5710000-20000 Kevin	5720000-30000 Kevin	5730000-40000 Kevin	5740000-50000 Kevin	5750000-60000 Kevin	5760000-70000 Kevin	5770000-80000 Kevin	5780000-90000 Kevin	5790000-00000 Kevin
5800000-10000 Kevin	5810000-20000 Kevin	5820000-30000 Kevin	5830000-40000 Kevin	5840000-50000 Kevin	5850000-60000 Kevin	5860000-70000 Kevin	5870000-80000 Kevin	5880000-90000 Kevin	5890000-00000 Kevin
5900000-10000 Kevin	5910000-20000 Kevin	5920000-30000 Kevin	5930000-40000 Kevin	5940000-50000 Kevin	5950000-60000 Kevin	5960000-70000 Kevin	5970000-80000 Kevin	5980000-90000 Kevin	5990000-00000 Kevin
6000000-10000 Daniel	6010000-20000 Daniel	6020000-30000 Lutz	6030000-40000 Lutz	6040000-50000 Anders	6050000-60000 Eric	6060000-70000 Eric	6070000-80000 Anders	6080000-90000 Daniel	6090000-00000 Daniel
6100000-10000 Kevin	6110000-20000 Kevin	6120000-30000 Kevin	6130000-40000 Kevin	6140000-50000 Kevin	6150000-60000 Kevin	6160000-70000 Kevin	6170000-80000 Kevin	6180000-90000 Kevin	6190000-00000 Kevin
6200000-10000 Kevin	6210000-20000 Kevin	6220000-30000 Kevin	6230000-40000 Kevin	6240000-50000 Kevin	6250000-60000 Kevin	6260000-70000 Kevin	6270000-80000 Kevin	6280000-90000 Kevin	6290000-00000 Kevin
6300000-10000 Kevin	6310000-20000 Kevin	6320000-30000 Kevin	6330000-40000 Kevin	6340000-50000 Kevin	6350000-60000 Kevin	6360000-70000 Kevin	6370000-80000 Kevin	6380000-90000 Kevin	6390000-00000 Kevin
6400000-10000 Kevin	6410000-20000 Kevin	6420000-30000 Kevin	6430000-40000 Kevin	6440000-50000 Kevin	6450000-60000 Kevin	6460000-70000 Kevin	6470000-80000 Kevin	6480000-90000 Kevin	6490000-00000 Kevin
6500000-10000 Volkmar	6510000-20000 Volkmar	6520000-30000 Volkmar	6530000-40000 Volkmar	6540000-50000 Volkmar	6550000-60000 Volkmar	6560000-70000 Volkmar	6570000-80000 Volkmar	6580000-90000 Volkmar	6590000-00000 Volkmar
6600000-10000 Anders	6610000-20000 Anders	6620000-30000 Lutz	6630000-40000 Lutz	6640000-50000 Daniel	6650000-60000 Daniel	6660000-70000 Sergey2	6670000-80000 Luiz	6680000-90000 Sergey2	6690000-00000 Eric
6700000-10000 Kevin	6710000-20000 Kevin	6720000-30000 Kevin	6730000-40000 Kevin	6740000-50000 Kevin	6750000-60000 Kevin	6760000-70000 Kevin	6770000-80000 Kevin	6780000-90000 Kevin	6790000-00000 Kevin
6800000-10000 Kevin	6810000-20000 Kevin	6820000-30000 Kevin	6830000-40000 Kevin	6840000-50000 Kevin	6850000-60000 Kevin	6860000-70000 Kevin	6870000-80000 Kevin	6880000-90000 Kevin	6890000-00000 Kevin
6900000-10000 Kevin	6910000-20000 Kevin	6920000-30000 Kevin	6930000-40000 Kevin	6940000-50000 Kevin	6950000-60000 Kevin	6960000-70000 Kevin	6970000-80000 Kevin	6980000-90000 Kevin	6990000-00000 Kevin
7000000-10000 Kevin	7010000-20000 Kevin	7020000-30000 Kevin	7030000-40000 Kevin	7040000-50000 Kevin	7050000-60000 Kevin	7060000-70000 Kevin	7070000-80000 Kevin	7080000-90000 Kevin	7090000-00000 Kevin
7100000-10000 Volkmar	7110000-20000 Volkmar	7120000-30000 Volkmar	7130000-40000 Volkmar	7140000-50000 Volkmar	7150000-60000 Volkmar	7160000-70000 Volkmar	7170000-80000 Volkmar	7180000-90000 Volkmar	7190000-00000 Volkmar
7200000-10000 Lutz	7210000-20000 Lutz	7220000-30000 Lutz	7230000-40000 Lutz	7240000-50000 Daniel	7250000-60000 Daniel	7260000-70000 Lutz	7270000-80000 Lutz	7280000-90000 Eric	7290000-00000 Eric
7300000-10000 Volkmar	7310000-20000 Volkmar	7320000-30000 Volkmar	7330000-40000 Volkmar	7340000-50000 Volkmar	7350000-60000 Volkmar	7360000-70000 Volkmar	7370000-80000 Volkmar	7380000-90000 Volkmar	7390000-00000 Volkmar
7400000-10000 Kevin	7410000-20000 Kevin	7420000-30000 Kevin	7430000-40000 Kevin	7440000-50000 Kevin	7450000-60000 Kevin	7460000-70000 Kevin	7470000-80000 Kevin	7480000-90000 Kevin	7490000-00000 Kevin
7500000-10000 Kevin	7510000-20000 Kevin	7520000-30000 Kevin	7530000-40000 Kevin	7540000-50000 Kevin	7550000-60000 Kevin	7560000-70000 Kevin	7570000-80000 Kevin	7580000-90000 Kevin	7590000-00000 Kevin
7600000-10000 Kevin	7610000-20000 Kevin	7620000-30000 Kevin	7630000-40000 Kevin	7640000-50000 Kevin	7650000-60000 Kevin	7660000-70000 Kevin	7670000-80000 Kevin	7680000-90000 Kevin	7690000-00000 Kevin
7700000-10000 Kevin	7710000-20000 Kevin	7720000-30000 Kevin	7730000-40000 Kevin	7740000-50000 Kevin	7750000-60000 Kevin	7760000-70000 Kevin	7770000-80000 Kevin	7780000-90000 Kevin	7790000-00000 Kevin
7800000-10000 Kevin	7810000-20000 Kevin	7820000-30000 Kevin	7830000-40000 Kevin	7840000-50000 Kevin	7850000-60000 Kevin	7860000-70000 Kevin	7870000-80000 Kevin	7880000-90000 Kevin	7890000-00000 Kevin
7900000-10000 Kevin	7910000-20000 Kevin	7920000-30000 Kevin	7930000-40000 Kevin	7940000-50000 Kevin	7950000-60000 Kevin	7960000-70000 Kevin	7970000-80000 Kevin	7980000-90000 Kevin	7990000-00000 Kevin
8000000-10000 Kevin	8010000-20000 Kevin	8020000-30000 Kevin	8030000-40000 Kevin	8040000-50000 Kevin	8050000-60000 Kevin	8060000-70000 Kevin	8070000-80000 Kevin	8080000-90000 Kevin	8090000-00000 Kevin
8100000-10000 Kevin	8110000-20000 Kevin	8120000-30000 Kevin	8130000-40000 Kevin	8140000-50000 Kevin	8150000-60000 Kevin	8160000-70000 Kevin	8170000-80000 Kevin	8180000-90000 Kevin	8190000-00000 Kevin
8200000-10000 Volkmar	8210000-20000 Volkmar	8220000-30000 Volkmar	8230000-40000 Volkmar	8240000-50000 Volkmar	8250000-60000 Volkmar	8260000-70000 Volkmar	8270000-80000 Volkmar	8280000-90000 Volkmar	8290000-00000 Volkmar
8300000-10000 Luiz	8310000-20000 Luiz	8320000-30000 Daniel	8330000-40000 Daniel	8340000-50000	8350000-60000	8360000-70000	8370000-80000	8380000-90000	8390000-00000
Contributions by Eric Eric Roosendaal, Netherlands (author) Lutz Lutz Nebe, Germany Kevin Kevin Hebb, Alberta, Canada Luiz Luiz Antonio Souza, Brazil Daniel Daniel Podobinski Volkmar Volkmar Schmidt Anders Anders Matre Sergey2 Sergey

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