nr p cfre cifre anno Scopritore (Computer) in Mp in P -- ------ ------ ------ ---- ---------------------- 1 2 1 1 - - 2 3 1 2 - - 3 5 2 3 - - 4 7 3 4 - - 5 13 4 8 1461 Anonimo 6 17 6 10 1588 Pietro Antonio Cataldi 7 19 6 12 1588 Pietro Antonio Cataldi 8 31 10 19 1750 Leonhard Euler 9 61 19 37 1883 I. M. Pervushin (calcolatore meccanico) 10 89 27 54 1911 R. E. Powers (calcolatore meccanico) 11 107 33 65 1914 R. E. Powers (calcolatore meccanico) 12 127 39 77 1876 Francois Edouard Anatole Lucas (calcolatore meccanico) 13 521 157 314 1952 Jan 30 Raphael M. Robinson (SWAC) 14 607 183 366 1952 Jan 30 Raphael M. Robinson (SWAC) 15 1279 386 770 1952 Jun 25 Raphael M. Robinson (SWAC) 16 2203 664 1327 1952 Oct 7 Raphael M. Robinson (SWAC) 17 2281 687 1373 1952 Oct 9 Raphael M. Robinson (SWAC) 18 3217 969 1937 1957 Hans Riesel (BESK) 19 4253 1281 2561 1961 Alexander Hurwitz & John L. Selfridge (IBM 7090) 20 4423 1332 2663 1961 Alexander Hurwitz & John L. Selfridge (IBM 7090) 21 9689 2917 5834 1963 Donald B. Gillies (ILLIAC 2) 22 9941 2993 5985 1963 Donald B. Gillies (ILLIAC 2) 23 11213 3376 6751 1963 Donald B. Gillies (ILLIAC 2) 24 19937 6002 12003 1971 Bryant Tuckerman (IBM 360/91) 25 21701 6533 13066 1978 Landon Curt Noll & Laura A. Nickel (Cyber 174) 26 23209 6987 13973 1979 Landon Curt Noll (Cyber 174) 27 44497 13395 26790 1979 David Slowinski & Harry L. Nelson (Cray 1) 28 86243 25962 51924 1982 David Slowinski (Cray 1) 29 110503 33265 66530 1988 Walter N. Colquitt & Luther Welsch, Jr. 30 132049 39751 79502 1983 David Slowinski (Cray X-MP) 31 216091 65050 130100 1985 David Slowinski (Cray X-MP) 32 756839 227832 455663 1992 David Slowinski & Paul Gage (Cray 2) 33 859433 258716 517430 1994 David Slowinski & Paul Gage (Cray C90) 34 1257787 378632 757263 1996 David Slowinski & Paul Gage (Cray T94) 35 1398269 420921 841842 1996 Joel Armengaud, George Woltman & GIMPS (PC Pentium 90) 36 2976221 895932 1791864 1997 Gordon Spence, George Woltman & GIMPS (PC Pentium 100) 37 3021377 909526 1819050 1998 Roland Clarkson, Woltman, Scott Kurowski & GIMPS (Pentium 200) 38 6972593 2098960 4197919 1999 Nayan Hajratwala, Woltman, Kurowski & GIMPS (Pentium II 350) 39 13466917 4053946 8107892 2001 Michael Cameron & GIMPS (800 MHz AMD T-Bird PC) 40 20996011 6320430 - - 2003 Michael Shafer & GIMPS (2 Gh Pentium 4 Dell Dimension PC) 41 24036583 7235733 - - 2004 Josh Findley & GIMPS (2.4 GHz Pentium 4 Windows XP PC)