3x+1 Class records calculation progress map
Status of the 3x+1 class record progress as of: Jul 27, 2010. Intervals are indicated in blocks of 20,000,000,000,000 (20 E+12 or 20 trillion numbers). Calculation of a single block takes approximately 20 days of (idle) time on a Pentium 1000 MHz. 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 Currently :  Countdown to 10.253 (~90,071 E+12) : 3 blocks to go. July 25 2010 :  All blocks up to 85,580 completed. One class record confirmed. April 30 2010 :  All blocks up to 83,800 completed. One class record confirmed. February 23 2010 :  All blocks up to 82,700 completed, passing 9.253. Two class records confirmed. January 26 2010 :  All blocks up to 76,420 completed. June 29 2009 :  All blocks up to 76,160 completed. The lowest missing CR (1964) and one other confirmed. April 30 2009 :  All blocks up to 72,520 completed, passing 256. Three class records confirmed. February 25 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)
Not yet assigned		Assigned, not yet started		Less than 50% completed		More than 50% completed		Entire interval completed
80000-20 Stephen	80020-40 Philippe	80040-60 Bo Sun	80060-80 Bernhard	80080-00 Bernhard	80100-20 Lutz	80120-40 Lutz	80140-60 Lutz	80160-80 Lutz	80180-00 Lutz
80200-20 Lutz	80220-40 Lutz	80240-60 Lutz	80260-80 Lutz	80280-00 Lutz	80300-20 Lutz	80320-40 Lutz	80340-60 Lutz	80360-80 Lutz	80380-00 Lutz
80400-20 Luiz	80420-40 Luiz	80440-60 Bob	80460-80 Bob	80480-00 Bob	80500-20 Peter P	80520-40 Bo Sun	80540-60 Stephen	80560-80 Nik	80580-00 Stephen
80600-20 Luiz	80620-40 Luiz	80640-60 Luiz	80660-80 Luiz	80680-00 Luiz	80700-20 Luiz	80720-40 Luiz	80740-60 Luiz	80760-80 Luiz	80780-00 Luiz
80800-20 Kevin	80820-40 Kevin	80840-60 Kevin	80860-80 Kevin	80880-00 Kevin	80900-20 Kevin	80920-40 Kevin	80940-60 Kevin	80960-80 Kevin	80980-00 Kevin
81000-20 Eric	81020-40 Eric	81040-60 Eric	81060-80 Eric	81080-00 Eric	81100-20 Eric	81120-40 Eric	81140-60 Eric	81160-80 Eric	81180-00 Eric
81200-20 Eric	81220-40 Eric	81240-60 Eric	81260-80 Eric	81280-00 Eric	81300-20 Eric	81320-40 Eric	81340-60 Eric	81360-80 Eric	81380-00 Eric
81400-20 Eric	81420-40 Eric	81440-60 Eric	81460-80 Eric	81480-00 Eric	81500-20 Eric	81520-40 Eric	81540-60 Eric	81560-80 Eric	81580-00 Eric
81600-20 Eric	81620-40 Eric	81640-60 Eric	81660-80 Eric	81680-00 Eric	81700-20 Eric	81720-40 Eric	81740-60 Eric	81760-80 Eric	81780-00 Eric
81800-20 Eric	81820-40 Eric	81840-60 Eric	81860-80 Eric	81880-00 Eric	81900-20 Eric	81920-40 Eric	81940-60 Eric	81960-80 Eric	81980-00 Eric
82000-20 Bob	82020-40 Bob	82040-60 Bob	82060-80 Bo Sun	82080-00 Nik	82100-20 Lutz	82120-40 Lutz	82140-60 Lutz	82160-80 Lutz	82180-00 Lutz
82200-20 Lutz	82220-40 Lutz	82240-60 Lutz	82260-80 Lutz	82280-00 Lutz	82300-20 Lutz	82320-40 Lutz	82340-60 Lutz	82360-80 Lutz	82380-00 Lutz
82400-20 Lutz	82420-40 Lutz	82440-60 Lutz	82460-80 Lutz	82480-00 Lutz	82500-20 Stephen	82520-40 Stephen	82540-60 Ken	82560-80 Ken	82580-00 Bo Sun
82600-20 Luiz	82620-40 Luiz	82640-60 Luiz	82660-80 Luiz	82680-00 Luiz	82700-20 Bob	82720-40 Bob	82740-60 Bob	82760-80 Bernhard	82780-00 Bernhard
82800-20 Lutz	82820-40 Lutz	82840-60 Lutz	82860-80 Lutz	82880-00 Lutz	82900-20 Lutz	82920-40 Lutz	82940-60 Lutz	82960-80 Lutz	82980-00 Lutz
83000-20 Stephen	83020-40 Lutz	83040-60 Lutz	83060-80 Lutz	83080-00 Lutz	83100-20 Lutz	83120-40 Lutz	83140-60 Lutz	83160-80 Lutz	83180-00 Lutz
83200-20 Nik	83220-40 Bob	83240-60 Nik	83260-80 Luiz	83280-00 Luiz	83300-20 Lutz	83320-40 Lutz	83340-60 Lutz	83360-80 Lutz	83380-00 Lutz
83400-20 Kevin	83420-40 Kevin	83440-60 Kevin	83460-80 Kevin	83480-00 Kevin	83500-20 Kevin	83520-40 Kevin	83540-60 Kevin	83560-80 Kevin	83580-00 Kevin
83600-20 Lutz	83620-40 Lutz	83640-60 Lutz	83660-80 Lutz	83680-00 Lutz	83700-20 Luiz	83720-40 Luiz	83740-60 Nik	83760-80 Stephen	83780-00 Stephen
83800-20 Eric	83820-40 Ken	83840-60 Ken	83860-80 Luiz	83880-00 Luiz	83900-20 Steven	83920-40 Steven	83940-60 Steven	83960-80 Steven	83980-00 Stephen
84000-20 Eric	84020-40 Eric	84040-60 Eric	84060-80 Eric	84080-00 Eric	84100-20 Eric	84120-40 Eric	84140-60 Eric	84160-80 Eric	84180-00 Eric
84200-20 Eric	84220-40 Eric	84240-60 Eric	84260-80 Eric	84280-00 Eric	84300-20 Eric	84320-40 Eric	84340-60 Eric	84360-80 Eric	84380-00 Eric
84400-20 Eric	84420-40 Eric	84440-60 Eric	84460-80 Eric	84480-00 Eric	84500-20 Eric	84520-40 Eric	84540-60 Eric	84560-80 Eric	84580-00 Eric
84600-20 Eric	84620-40 Eric	84640-60 Eric	84660-80 Eric	84680-00 Eric	84700-20 Eric	84720-40 Eric	84740-60 Eric	84760-80 Eric	84780-00 Eric
84800-20 Eric	84820-40 Eric	84840-60 Eric	84860-80 Eric	84880-00 Eric	84900-20 Eric	84920-40 Eric	84940-60 Eric	84960-80 Eric	84980-00 Eric
85000-20 Lutz	85020-40 Lutz	85040-60 Lutz	85060-80 Lutz	85080-00 Lutz	85100-20 Lutz	85120-40 Lutz	85140-60 Lutz	85160-80 Lutz	85180-00 Lutz
85200-20 Lutz	85220-40 Lutz	85240-60 Lutz	85260-80 Lutz	85280-00 Lutz	85300-20 Lutz	85320-40 Lutz	85340-60 Lutz	85360-80 Lutz	85380-00 Lutz
85400-20 Stephen	85420-40 Bob	85440-60 Bob	85460-80 Bob	85480-00 Jasper	85500-20 Luiz	85520-40 Luiz	85540-60 Luiz	85560-80 Luiz	85580-00 Philippe
85600-20 Bob	85620-40 Bob	85640-60 Bob	85660-80 Bob	85680-00 Bob	85700-20 Luiz	85720-40 Luiz	85740-60 Luiz	85760-80 Bernhard	85780-00 Bernhard
85800-20 Kevin	85820-40 Kevin	85840-60 Kevin	85860-80 Kevin	85880-00 Kevin	85900-20 Kevin	85920-40 Kevin	85940-60 Kevin	85960-80 Kevin	85980-00 Kevin
86000-20 Kevin	86020-40 Kevin	86040-60 Kevin	86060-80 Kevin	86080-00 Kevin	86100-20 Kevin	86120-40 Kevin	86140-60 Kevin	86160-80 Kevin	86180-00 Kevin
86200-20 Lutz	86220-40 Lutz	86240-60 Lutz	86260-80 Lutz	86280-00 Lutz	86300-20 Lutz	86320-40 Lutz	86340-60 Lutz	86360-80 Lutz	86380-00 Lutz
86400-20 Lutz	86420-40 Lutz	86440-60 Lutz	86460-80 Lutz	86480-00 Lutz	86500-20 Lutz	86520-40 Lutz	86540-60 Lutz	86560-80 Lutz	86580-00 Lutz
86600-20 Bob	86620-40 Bob	86640-60 Bob	86660-80 Eric	86680-00 Stephen	86700-20 Luiz	86720-40 Luiz	86740-60 Luiz	86760-80 Luiz	86780-00 Luiz
86800-20 Jasper	86820-40 Bob	86840-60 Bob	86860-80 Bob	86880-00 Tony	86900-20 Luiz	86920-40 Luiz	86940-60 Luiz	86960-80 Luiz	86980-00 Stephen
87000-20 Eric	87020-40 Eric	87040-60 Eric	87060-80 Eric	87080-00 Eric	87100-20 Eric	87120-40 Eric	87140-60 Eric	87160-80 Eric	87180-00 Eric
87200-20 Eric	87220-40 Eric	87240-60 Eric	87260-80 Eric	87280-00 Eric	87300-20 Eric	87320-40 Eric	87340-60 Eric	87360-80 Eric	87380-00 Eric
87400-20 Eric	87420-40 Eric	87440-60 Eric	87460-80 Eric	87480-00 Eric	87500-20 Eric	87520-40 Eric	87540-60 Eric	87560-80 Eric	87580-00 Eric
87600-20 Eric	87620-40 Eric	87640-60 Eric	87660-80 Eric	87680-00 Eric	87700-20 Eric	87720-40 Eric	87740-60 Eric	87760-80 Eric	87780-00 Eric
87800-20 Eric	87820-40 Eric	87840-60 Eric	87860-80 Eric	87880-00 Eric	87900-20 Eric	87920-40 Eric	87940-60 Eric	87960-80 Eric	87980-00 Eric
88000-20 Kevin	88020-40 Kevin	88040-60 Kevin	88060-80 Kevin	88080-00 Kevin	88100-20 Kevin	88120-40 Kevin	88140-60 Kevin	88160-80 Kevin	88180-00 Kevin
88200-20 Kevin	88220-40 Kevin	88240-60 Kevin	88260-80 Kevin	88280-00 Kevin	88300-20 Kevin	88320-40 Kevin	88340-60 Kevin	88360-80 Kevin	88380-00 Kevin
88400-20 Kevin	88420-40 Kevin	88440-60 Kevin	88460-80 Kevin	88480-00 Kevin	88500-20 Kevin	88520-40 Kevin	88540-60 Kevin	88560-80 Kevin	88580-00 Kevin
88600-20 Kevin	88620-40 Kevin	88640-60 Kevin	88660-80 Kevin	88680-00 Kevin	88700-20 Kevin	88720-40 Kevin	88740-60 Kevin	88760-80 Kevin	88780-00 Kevin
88800-20 Kevin	88820-40 Kevin	88840-60 Kevin	88860-80 Kevin	88880-00 Kevin	88900-20 Kevin	88920-40 Kevin	88940-60 Kevin	88960-80 Kevin	88980-00 Kevin
89000-20 Eric	89020-40 Eric	89040-60 Eric	89060-80 Eric	89080-00 Eric	89100-20 Eric	89120-40 Eric	89140-60 Eric	89160-80 Eric	89180-00 Eric
89200-20 Eric	89220-40 Eric	89240-60 Eric	89260-80 Eric	89280-00 Eric	89300-20 Eric	89320-40 Eric	89340-60 Eric	89360-80 Eric	89380-00 Eric
89400-20 Eric	89420-40 Eric	89440-60 Eric	89460-80 Eric	89480-00 Eric	89500-20 Eric	89520-40 Eric	89540-60 Eric	89560-80 Eric	89580-00 Eric
89600-20 Eric	89620-40 Eric	89640-60 Eric	89660-80 Eric	89680-00 Eric	89700-20 Eric	89720-40 Eric	89740-60 Eric	89760-80 Eric	89780-00 Eric
89800-20 Eric	89820-40 Eric	89840-60 Eric	89860-80 Eric	89880-00 Eric	89900-20 Eric	89920-40 Eric	89940-60 Eric	89960-80 Eric	89980-00 Eric
90000-20 Bernhard	90020-40 Bernhard	90040-60 Stephen	90060-80 Stephen	90080-00 Luiz	90100-20 Lutz	90120-40 Lutz	90140-60 Lutz	90160-80 Lutz	90180-00 Lutz
90200-20 Lutz	90220-40 Lutz	90240-60 Lutz	90260-80 Lutz	90280-00 Lutz	90300-20 Lutz	90320-40 Lutz	90340-60 Lutz	90360-80 Lutz	90380-00 Lutz
90400-20 Lutz	90420-40 Lutz	90440-60 Lutz	90460-80 Lutz	90480-00 Lutz	90500-20 Lutz	90520-40 Lutz	90540-60 Lutz	90560-80 Lutz	90580-00 Lutz
90600-20 Lutz	90620-40 Lutz	90640-60 Lutz	90660-80 Lutz	90680-00 Lutz	90700-20 Ken	90720-40 Ken	90740-60 Luiz	90760-80 Luiz	90780-00 Luiz
90800-20 Kevin	90820-40 Kevin	90840-60 Kevin	90860-80 Kevin	90880-00 Kevin	90900-20 Kevin	90920-40 Kevin	90940-60 Kevin	90960-80 Kevin	90980-00 Kevin
91000-20 Kevin	91020-40 Kevin	91040-60 Kevin	91060-80 Kevin	91080-00 Kevin	91100-20 Kevin	91120-40 Kevin	91140-60 Kevin	91160-80 Kevin	91180-00 Kevin
91200-20 Kevin	91220-40 Kevin	91240-60 Kevin	91260-80 Kevin	91280-00 Kevin	91300-20 Kevin	91320-40 Kevin	91340-60 Kevin	91360-80 Kevin	91380-00 Kevin
91400-20 Bob	91420-40 Bob	91440-60 Bob	91460-80 Patrick	91480-00 Luiz	91500-20 Luiz	91520-40 Luiz	91540-60 Luiz	91560-80 Luiz	91580-00 Luiz
91600-20 Bob	91620-40 Bob	91640-60 Bob	91660-80 Bob	91680-00 Bob	91700-20 Patrick	91720-40 Grisous	91740-60 Stephen	91760-80 Stephen	91780-00 Jasper
91800-20 Steven	91820-40 Steven	91840-60 Steven	91860-80 Steven	91880-00 Vladimir	91900-20 Lutz	91920-40 Lutz	91940-60 Lutz	91960-80 Lutz	91980-00 Lutz
92000-20 Lutz	92020-40 Lutz	92040-60 Lutz	92060-80 Lutz	92080-00 Lutz	92100-20 Lutz	92120-40 Lutz	92140-60 Lutz	92160-80 Lutz	92180-00 Lutz
92200-20 Lutz	92220-40 Lutz	92240-60 Lutz	92260-80 Lutz	92280-00 Lutz	92300-20 Lutz	92320-40 Lutz	92340-60 Lutz	92360-80 Lutz	92380-00 Lutz
92400-20 Lutz	92420-40 Lutz	92440-60 Lutz	92460-80 Lutz	92480-00 Lutz	92500-20 Steven	92520-40 Steven	92540-60 Steven	92560-80 Steven	92580-00 Jasper
92600-20	92620-40	92640-60	92660-80	92680-00	92700-20	92720-40	92740-60	92760-80	92780-00
92800-20	92820-40	92840-60	92860-80	92880-00	92900-20 Bob	92920-40 Bob	92940-60 Bob	92960-80 Patrick	92980-00 Stephen
93000-20 Eric	93020-40 Eric	93040-60 Eric	93060-80 Eric	93080-00 Eric	93100-20 Eric	93120-40 Eric	93140-60 Eric	93160-80 Eric	93180-00 Eric
93200-20 Eric	93220-40 Eric	93240-60 Eric	93260-80 Eric	93280-00 Eric	93300-20 Eric	93320-40 Eric	93340-60 Eric	93360-80 Eric	93380-00 Eric
93400-20 Eric	93420-40 Eric	93440-60 Eric	93460-80 Eric	93480-00 Eric	93500-20 Eric	93520-40 Eric	93540-60 Eric	93560-80 Eric	93580-00 Eric
93600-20 Eric	93620-40 Eric	93640-60 Eric	93660-80 Eric	93680-00 Eric	93700-20 Eric	93720-40 Eric	93740-60 Eric	93760-80 Eric	93780-00 Eric
93800-20 Eric	93820-40 Eric	93840-60 Eric	93860-80 Eric	93880-00 Eric	93900-20 Eric	93920-40 Eric	93940-60 Eric	93960-80 Eric	93980-00 Eric
94000-20 Kevin	94020-40 Kevin	94040-60 Kevin	94060-80 Kevin	94080-00 Kevin	94100-20 Kevin	94120-40 Kevin	94140-60 Kevin	94160-80 Kevin	94180-00 Kevin
94200-20 Kevin	94220-40 Kevin	94240-60 Kevin	94260-80 Kevin	94280-00 Kevin	94300-20 Kevin	94320-40 Kevin	94340-60 Kevin	94360-80 Kevin	94380-00 Kevin
94400-20 Kevin	94420-40 Kevin	94440-60 Kevin	94460-80 Kevin	94480-00 Kevin	94500-20 Kevin	94520-40 Kevin	94540-60 Kevin	94560-80 Kevin	94580-00 Kevin
94600-20 Kevin	94620-40 Kevin	94640-60 Kevin	94660-80 Kevin	94680-00 Kevin	94700-20 Kevin	94720-40 Kevin	94740-60 Kevin	94760-80 Kevin	94780-00 Kevin
94800-20 Kevin	94820-40 Kevin	94840-60 Kevin	94860-80 Kevin	94880-00 Kevin	94900-20 Kevin	94920-40 Kevin	94940-60 Kevin	94960-80 Kevin	94980-00 Kevin
95000-20 Eric	95020-40 Eric	95040-60 Eric	95060-80 Eric	95080-00 Eric	95100-20 Eric	95120-40 Eric	95140-60 Eric	95160-80 Eric	95180-00 Eric
95200-20 Eric	95220-40 Eric	95240-60 Eric	95260-80 Eric	95280-00 Eric	95300-20 Eric	95320-40 Eric	95340-60 Eric	95360-80 Eric	95380-00 Eric
95400-20 Eric	95420-40 Eric	95440-60 Eric	95460-80 Eric	95480-00 Eric	95500-20 Eric	95520-40 Eric	95540-60 Eric	95560-80 Eric	95580-00 Eric
95600-20 Eric	95620-40 Eric	95640-60 Eric	95660-80 Eric	95680-00 Eric	95700-20 Eric	95720-40 Eric	95740-60 Eric	95760-80 Eric	95780-00 Eric
95800-20 Eric	95820-40 Eric	95840-60 Eric	95860-80 Eric	95880-00 Eric	95900-20 Eric	95920-40 Eric	95940-60 Eric	95960-80 Eric	95980-00 Eric
Contributions by Eric Eric Roosendaal, Netherlands (author) Lutz Lutz Nebe, Germany Kevin Kevin Hebb, Alberta, Canada Ken Ken Monks, Pennsylvania, USA Bob Bob Coffman, USA Bernhard Bernhard Willems, Germany Steven Steven Cuthbert, England Luiz Luiz Antonio Souza, Brazil Stephen Stephen Dickason Nik Nik Lygeros, Greece Philippe Philippe Cholet, France Bo Sun Bo Sun, China Peter P Peter Phipps Jasper Jasper Mulder, Netherlands Tony Tony Galvan Patrick Patrick Chauvet, France Grisous Grisous, France Vladimir Vladimir Romanov, Russia

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