3x+1 Class records calculation progress map
Status of the 3x+1 class record progress as of: Sep 23, 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.
Trajectory of 63,728,127
Progress history
August 29 2022 : All blocks up to 16,400 completed. Four more class records confirmed.
June 30 2022 : All blocks up to 15,140 completed. One more class record confirmed.
May 22 2022 : All blocks up to 15,000 completed. Delay record 2442 and six more class record confirmed.
May 7 2022 : Possible Delay record (Delay 2442) found by Kevin.
March 30 2022 : All blocks up to 13,480 completed. Delay record 2429 and four more class record confirmed.
February 10 2022 : Possible new Delay record (Delay 2429) found by Kevin.
January 31 2022 : All blocks up to 12,300 completed. Six more class records confirmed.
December 26 2021 : All blocks up to 10,820 completed. Three more class records confirmed.
November 15 2021 : All blocks up to 10,090 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.
Show/Hide earlier milestones
December 2020 : All blocks up to 3940,000 completed. Delay record 2334 and ten more class records confirmed.
December 15 2020 : Possible new Delay record (Delay 2334) found by Kevin.
November 2020 : All blocks up to 2900,000 completed. Delay record 2331 and twelve more class records confirmed
September 2020 : All blocks up to 2300,000 completed. Eleven more class records confirmed
September 2020 : All blocks up to 2000,000 completed. Fifteen more class records confirmed
August 2020 : All blocks up to 1620,000 completed. Delay record 2330 and fifteen more class records confirmed
July 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.
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)
Range 10000000-15000000
completed (view)
 
Not yet assigned Assigned,
not yet started
Assigned,
in progress
Entire interval
completed
Interval completed
class record found
15000000-10000
Kevin
15010000-20000
Kevin
15020000-30000
Kevin
15030000-40000
Kevin
15040000-50000
Kevin
15050000-60000
Kevin
15060000-70000
Kevin
15070000-80000
Kevin
15080000-90000
Kevin
15090000-00000
Kevin
15100000-10000
Daniel
15110000-20000
Daniel
15120000-30000
Wenjie
15130000-40000
Wenjie
15140000-50000
Lutz
15150000-60000
Lutz
15160000-70000
Luiz
15170000-80000
Luiz
15180000-90000
Eric
15190000-00000
Eric
15200000-10000
Kevin
15210000-20000
Kevin
15220000-30000
Kevin
15230000-40000
Kevin
15240000-50000
Kevin
15250000-60000
Kevin
15260000-70000
Kevin
15270000-80000
Kevin
15280000-90000
Kevin
15290000-00000
Kevin
15300000-10000
Kevin
15310000-20000
Kevin
15320000-30000
Kevin
15330000-40000
Kevin
15340000-50000
Kevin
15350000-60000
Kevin
15360000-70000
Kevin
15370000-80000
Kevin
15380000-90000
Kevin
15390000-00000
Kevin
15400000-10000
Kevin
15410000-20000
Kevin
15420000-30000
Kevin
15430000-40000
Kevin
15440000-50000
Kevin
15450000-60000
Kevin
15460000-70000
Kevin
15470000-80000
Kevin
15480000-90000
Kevin
15490000-00000
Kevin
15500000-10000
Kevin
15510000-20000
Kevin
15520000-30000
Kevin
15530000-40000
Kevin
15540000-50000
Kevin
15550000-60000
Kevin
15560000-70000
Kevin
15570000-80000
Kevin
15580000-90000
Kevin
15590000-00000
Kevin
15600000-10000
Volkmar
15610000-20000
Volkmar
15620000-30000
Volkmar
15630000-40000
Volkmar
15640000-50000
Volkmar
15650000-60000
Volkmar
15660000-70000
Volkmar
15670000-80000
Volkmar
15680000-90000
Volkmar
15690000-00000
Volkmar
15700000-10000
Eric
15710000-20000
Eric
15720000-30000
Daniel
15730000-40000
Daniel
15740000-50000
Wenjie
15750000-60000
Wenjie
15760000-70000
Luiz
15770000-80000
Luiz
15780000-90000
Eric
15790000-00000
Bruce M
15800000-10000
Volkmar
15810000-20000
Volkmar
15820000-30000
Volkmar
15830000-40000
Volkmar
15840000-50000
Volkmar
15850000-60000
Volkmar
15860000-70000
Volkmar
15870000-80000
Volkmar
15880000-90000
Volkmar
15890000-00000
Volkmar
15900000-10000
Volkmar
15910000-20000
Volkmar
15920000-30000
Volkmar
15930000-40000
Volkmar
15940000-50000
Volkmar
15950000-60000
Volkmar
15960000-70000
Volkmar
15970000-80000
Volkmar
15980000-90000
Volkmar
15990000-00000
Volkmar
16000000-10000
Kevin
16010000-20000
Kevin
16020000-30000
Kevin
16030000-40000
Kevin
16040000-50000
Kevin
16050000-60000
Kevin
16060000-70000
Kevin
16070000-80000
Kevin
16080000-90000
Kevin
16090000-00000
Kevin
16100000-10000
Kevin
16110000-20000
Kevin
16120000-30000
Kevin
16130000-40000
Kevin
16140000-50000
Kevin
16150000-60000
Kevin
16160000-70000
Kevin
16170000-80000
Kevin
16180000-90000
Kevin
16190000-00000
Kevin
16200000-10000
Kevin
16210000-20000
Kevin
16220000-30000
Kevin
16230000-40000
Kevin
16240000-50000
Kevin
16250000-60000
Kevin
16260000-70000
Kevin
16270000-80000
Kevin
16280000-90000
Kevin
16290000-00000
Kevin
16300000-10000
Kevin
16310000-20000
Kevin
16320000-30000
Kevin
16330000-40000
Kevin
16340000-50000
Kevin
16350000-60000
Kevin
16360000-70000
Kevin
16370000-80000
Kevin
16380000-90000
Kevin
16390000-00000
Kevin
16400000-10000
Daniel
16410000-20000
Daniel
16420000-30000
Wenjie
16430000-40000
Wenjie
16440000-50000
Luiz
16450000-60000
Luiz
16460000-70000
Luiz
16470000-80000
Luiz
16480000-90000
Lutz
16490000-00000
Lutz
16500000-10000
Volkmar
16510000-20000
Volkmar
16520000-30000
Volkmar
16530000-40000
Volkmar
16540000-50000
Volkmar
16550000-60000
Volkmar
16560000-70000
Volkmar
16570000-80000
Volkmar
16580000-90000
Volkmar
16590000-00000
Volkmar
16600000-10000
Kevin
16610000-20000
Kevin
16620000-30000
Kevin
16630000-40000
Kevin
16640000-50000
Kevin
16650000-60000
Kevin
16660000-70000
Kevin
16670000-80000
Kevin
16680000-90000
Kevin
16690000-00000
Kevin
16700000-10000
Kevin
16710000-20000
Kevin
16720000-30000
Kevin
16730000-40000
Kevin
16740000-50000
Kevin
16750000-60000
Kevin
16760000-70000
Kevin
16770000-80000
Kevin
16780000-90000
Kevin
16790000-00000
Kevin
16800000-10000
Kevin
16810000-20000
Kevin
16820000-30000
Kevin
16830000-40000
Kevin
16840000-50000
Kevin
16850000-60000
Kevin
16860000-70000
Kevin
16870000-80000
Kevin
16880000-90000
Kevin
16890000-00000
Kevin
16900000-10000
Kevin
16910000-20000
Kevin
16920000-30000
Kevin
16930000-40000
Kevin
16940000-50000
Kevin
16950000-60000
Kevin
16960000-70000
Kevin
16970000-80000
Kevin
16980000-90000
Kevin
16990000-00000
Kevin
17000000-10000
Volkmar
17010000-20000
Volkmar
17020000-30000
Volkmar
17030000-40000
Volkmar
17040000-50000
Volkmar
17050000-60000
Volkmar
17060000-70000
Volkmar
17070000-80000
Volkmar
17080000-90000
Volkmar
17090000-00000
Volkmar
17100000-10000
Wenjie
17110000-20000
Wenjie
17120000-30000
17130000-40000
17140000-50000
17150000-60000
17160000-70000
17170000-80000
17180000-90000
17190000-00000
17200000-10000
Kevin
17210000-20000
Kevin
17220000-30000
Kevin
17230000-40000
Kevin
17240000-50000
Kevin
17250000-60000
Kevin
17260000-70000
Kevin
17270000-80000
Kevin
17280000-90000
Kevin
17290000-00000
Kevin
17300000-10000
Kevin
17310000-20000
Kevin
17320000-30000
Kevin
17330000-40000
Kevin
17340000-50000
Kevin
17350000-60000
Kevin
17360000-70000
Kevin
17370000-80000
Kevin
17380000-90000
Kevin
17390000-00000
Kevin
17400000-10000
Kevin
17410000-20000
Kevin
17420000-30000
Kevin
17430000-40000
Kevin
17440000-50000
Kevin
17450000-60000
Kevin
17460000-70000
Kevin
17470000-80000
Kevin
17480000-90000
Kevin
17490000-00000
Kevin
17500000-10000
Kevin
17510000-20000
Kevin
17520000-30000
Kevin
17530000-40000
Kevin
17540000-50000
Kevin
17550000-60000
Kevin
17560000-70000
Kevin
17570000-80000
Kevin
17580000-90000
Kevin
17590000-00000
Kevin
Contributions by
EricEric Roosendaal, Netherlands (author) LutzLutz Nebe, Germany
KevinKevin Hebb, Alberta, Canada WenjieFang Wenjie, China
LuizLuiz Antonio Souza, Brazil DanielDaniel Podobinski
VolkmarVolkmar Schmidt Bruce MBruce M, USA,

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