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Sieving was done rapidly on Core 2 Duos at my university (NIT, Trichy) which helped me to sieve rapidly at that time.
When vacation started on 29 Apr 2008, the sieving was 86% done on this number. After that for 20 days, I was without any resources, so sieving was suspended On 20 May 2008, we bought a new Core 2 Quad @ 2.4 GHz at home which helped to finish the sieving rapidly. Around June 9th the sieving was sufficient enough with about 78 million special-q sieved. Five days ago, the linear algebra was started on my Core 2 Duo laptop @ 1.7 GHz. Since there wasn't enough virtual memory available in normal mode, the post processing went in safe mode with the /3GB switch. Regarding square root, each dependency takes about two hours to solve it up, the first dependency failed. Cleverly simultaneously I picked up the 4th dependency on the other core of my laptop. The dependency was a good choice to give me away with the factors! I have chosen up with the fourth dependency in the square root stage because 2,1039- gave away the factors at the 4th dependency! Notice that 6,305- took 8 months to complete. But 7,295- which is twice as harder took only 6 months, eventhough I was idle for sometime between. Sieving was rushed through with those Core 2 Duos at my college. 10,312+ is half-way through sieved. It will take a couple of weeks if 30 million special-q suffice. |
[QUOTE=Raman;136494]7,295-
[CODE] Tue Jun 24 00:30:50 2008 prp81 factor: 204239004182680605398190478754212368873366912490836010105265524712426411236134031 Tue Jun 24 00:30:51 2008 prp111 factor: 393263672474017252292660491631044385409360056708958704520879019006886885032467377758314801669636946200575798561 [/CODE] One minute... Let me mail Prof. Sam Wagstaff before posting further information about it...[/QUOTE]Nice one! I'm glad it worked out in the end. Good luck with the next. Paul |
[quote=xilman;136497]
Nice one! I'm glad it worked out in the end. Good luck with the next. [/quote] What is the best polynomial that I can use so for 10,375- Since 3 and 5 both divide 375, So, the polynomial that I currently think so of, is x[sup]10[/sup]+x[sup]5[/sup]+1 divided by x[sup]2[/sup]+x+1 which is, [tex]x^8-x^7+x^5-x^4+x^3-x+1[/tex] which has SNFS difficulty of 200 digits |
[QUOTE=Raman;136500]
[tex]x^8-x^7+x^5-x^4+x^3-x+1[/tex] which has SNFS difficulty of 200 digits[/QUOTE] Yep, but make it degree 4. Not great, but the best you can do. [TEX]x^4-x^3-4x^2+4x+1[/TEX] [TEX]10^{25}x-(10^{50}+1)[/TEX] Greg |
[quote=frmky;136505]
Yep, but make it degree 4. Not great, but the best you can do. [tex]x^4-x^3-4x^2+4x+1[/tex] [tex]10^{25}x-(10^{50}+1)[/tex] [/quote] Sure? Is biquadratic (aka quartic) the best polynomial that I can use so for 10,375-? No quintics or sextics are available for it, of course with difficulty 200? And eighth degree is not feasible? I think that it makes the algebraic coefficients too larger, right? [code] Similarly I think that for a multiple of 11, say 7,319- you will certainly not be using [tex]\sum_{i=0}^{10} x^i[/tex] and [tex]x-7^{29}[/tex] You would be reducing it to degree 5, right? And for a multiple of 13, for example 6,299- [tex]\sum_{i=0}^{12} x^i[/tex] should be reduced to degree 6. Although both of these are reduced to degree 5 and 6, a multiple of 17 or higher cannot be reduced this way to degree 8 or higher and should be treated up as a prime exponent, right? For example, for 2,799- Dr. Kleinjung et al. would certainly not have used [tex]\sum_{i=0}^{16} x^i[/tex] and [tex]x-2^{47}[/tex] or of course, the one reduced up to degree 8 for it. I think that they would only have used up so with [tex]2x^6-1[/tex] and [tex]x-2^{133}[/tex] in the Bonn University. [/code]What about reducing the degree 14 for 10,375- (since it is a multiple of 15) this way up to degree 7 directly? [tex]\sum_{i=0}^{14} x^i[/tex] and [tex]x-10^{25}[/tex] |
[QUOTE=Raman;136580]Sure? Is biquadratic (aka quartic) the best polynomial that I can use so
for 10,375-? No quintics or sextics are available for it, of course with difficulty 200? And eighth degree is not feasible? I think that it makes the algebraic coefficients too larger, right? [/QUOTE] Correct, the algebraic sieve values grow too large too quickly, so the number of algebraic sieve values that are smooth enough drops too fast. The asymptotic estimates for NFS indicate that a degree-7 polynomial is feasible only for inputs that have many hundreds, if not thousands, of digits. Most of the smallest cunningham numbers that are left have similar difficulty; if an available cunningham number is unusually small, it's probably because the NFS polynomials involved are unusually bad :) |
[QUOTE=jasonp;136586]Correct, the algebraic sieve values grow too large too quickly, so the number of algebraic sieve values that are smooth enough drops too fast. The asymptotic estimates for NFS indicate that a degree-7 polynomial is feasible only for inputs that have many hundreds, if not thousands, of digits.
Most of the smallest cunningham numbers that are left have similar difficulty; if an available cunningham number is unusually small, it's probably because the NFS polynomials involved are unusually bad :)[/QUOTE] Actually, there are a fair number of composites left under 230 digits that do not require a quartic. 10,312+ Raman; in progress 2,2106L quartic; yech 10,378+ 7,384+ 5,341- reserved 2,1694M 3,517+ I will do shortly 7,393+ 2,1104+ in progress; LA 75% 10,259+ 10,339- 2,1119+ 2,1128+ 2,1149- 2,1161+ 2,1161- 10,339+ 7,396+ |
I'm about to start 10,259+ if nobody else is interested in it.
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I'm going after 10,339-
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[QUOTE=R.D. Silverman;136655]Actually, there are a fair number of composites left under 230 digits that
do not require a quartic. 10,312+ Raman; in progress 2,2106L quartic; yech 10,378+ 7,384+ 5,341- reserved 2,1694M 3,517+ I will do shortly 7,393+ 2,1104+ in progress; LA 75% 10,259+ 10,339- 2,1119+ 2,1128+ 2,1149- 2,1161+ 2,1161- 10,339+ 7,396+[/QUOTE] And there are also lots of them that do require a quartic: 3,565-, 580+ 6,335- 6,370+ 5,370+, 400+, 410+ 430+ 7,335- 320+, 340+ 2,860+, 865+, 925+..... etc. etc. etc. 7,320+, 340+ 3,580+ |
[quote=frmky;136505]Yep, but make it degree 4. Not great, but the best you can do.
[tex]x^4-x^3-4x^2+4x+1[/tex] [tex]10^{25}x-(10^{50}+1)[/tex] Greg [/quote] So, can you please explain to me up how you derived the 4th degree polynomial from the 8th degree one for [tex]10,375-[/tex] [tex]x^8-x^7+x^5-x^4+x^3-x+1[/tex] [tex]x-10^{25}[/tex] I am starting to sieve for 10,375- now. 10,312+ is in Linear Algebra and will finish up within about 12 hours or so (Matrix has less than 20 million rows!) :exclaim: [SIZE=4]EMERGENCY[/SIZE] Also that I can't enter the value of [B]m[/B] in the GGNFS poly file too, because of the fact that [tex]\division_{10^{25}}^{(10^{50}+1)}[/tex] is again not an integer at all |
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