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.
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 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 Bruce M Bruce M, USA,

Back to the general 3x+1 page.