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[QUOTE=rogue;452752]
I was not aware that you had resurrected the search. If your site is more complete than mine, then I can redirect to your site. Are you aware of all of the multifactorial primes that were missed by other searchers? Have you included those in your list?[/QUOTE] On my webpage, I have put all Kevin's results. I have been verifying only the results of multifactorial primes with digits <= 10,000. I haven't verified the rest. The list of all multifactorial primes I have tested by myself is included in the file: [URL]http://mfprimes.republika.pl/Range_mfp_marian_otremba.txt[/URL] I have also added your new results that were missing in mine and Kevin's data. IMHO the results on my page are complete. Right now I am searching multifactorial primes (n!k+-1) with digits <= 10,000 and k = 102..200 |
[QUOTE=rogue;452753]559741!7+1 is prime! :razz:
If I computed the length correctly, that is 424902 digits! Once submitted it will be around position 2800 in the Top 5000 and will set a new record for the form. [/QUOTE] Congrats ! I verified this result Primality testing 559741!7+1 [N-1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 79967 Calling Brillhart-Lehmer-Selfridge with factored part 33.95% 559741!7+1 is prime! (4675.2281s+2.1494s) (digits 424902) Mark Rodenkirch 02/2017 OK |
[QUOTE=rogue;452753]559741![SUB]7[/SUB]+1 is prime! :razz:
[/QUOTE] Because 7 | 559741, it can also be written as 559741![SUB]7[/SUB]+1 = 79963! * 7[SUP]79963[/SUP] + 1. What values (mod 7) are left in the sieve, out of curiosity? And why is it not submitted to UTM? |
[QUOTE=Batalov;452978]Because 7 | 559741, it can also be written as
559741![SUB]7[/SUB]+1 = 79963! * 7[SUP]79963[/SUP] + 1. What values (mod 7) are left in the sieve, out of curiosity? And why is it not submitted to UTM?[/QUOTE] I do not understand your first question. It is not submitted to UTM because [URL="http://primes.utm.edu/bios/page.php?id=2474"]this[/URL] is not owned by me (even though it has my name) and I need to add mfsieve to it. Chris hasn't responded to me yet. |
[QUOTE=rogue;452985]...because [URL="http://primes.utm.edu/bios/page.php?id=2474"]this[/URL] is not owned by me (even though it has my name) [/QUOTE]
Wow! This is very unusual. __ __ __ __ __ __ Re: first question. Clearly, x![SUB]m[/SUB] [TEX]\pm[/TEX] 1 has strong implications on the survivor values of x (mod m) after sieving with small primes. Take m=2, for example. Can x be odd and x![SUB]2[/SUB] [TEX]\pm[/TEX] 1 prime? Clearly not ([I]except for[/I] trivial 1![SUB]2[/SUB] + 1 and 3![SUB]2[/SUB] - 1, where both equal two 2, obviously. All other even numbers are not prime.). Now, because x must be even, for the rest of the sieve, you get only (2x)![SUB]2[/SUB] [TEX]\pm[/TEX] 1,which is equal to x! * 2[SUP]x[/SUP][TEX]\pm[/TEX] 1 which doesn't require an explanation what "![SUB]2[/SUB]" or "!!" exactly is. Well, almost everyone knows what "!" means without an explanation. So, my question was about the same for m=7. And because you have the sieve file, I expected just simple stats, not a theory. (Apparently I can exclude x=1 (mod 7) for the "-1" form.) But that's ok; I left the m=7 sieve running and will have a look at my own copy of the sieve file tomorrow morning... |
[QUOTE=rogue;452985]It is not submitted to UTM because [URL="http://primes.utm.edu/bios/page.php?id=2474"]this[/URL] is not owned by me (even though it has my name) and I need to add mfsieve to it. Chris hasn't responded to me yet.[/QUOTE]
If that entry is going to be modified, it could always be done after the fact, can't it? |
[QUOTE=axn;453006]If that entry is going to be modified, it could always be done after the fact, can't it?[/QUOTE]
Yes, I will probably do that. |
[QUOTE=Batalov;452978]Because 7 | 559741, it can also be written as
559741![SUB]7[/SUB]+1 = 79963! * 7[SUP]79963[/SUP] + 1. [/QUOTE] The same case holds for mfp+1 (n!7+1) n -> (35 = 5*7, 49 = 7^2, 147 = 3*7^2, 336 = 2^4*3*7, 2079 = 3^3*7*11, 8855 = 5*7*11*23, 20636 = 2^2*7*11*67, 22988 = 2^2*7*821, 41139 = 3^2*7*653, 208502 = 2*7*53*281, 559741 = 7*13*6151) and for mfp-1 (n!7-1) n -> (14 = 2*7, 98 = 2*7^2, 371 = 7*53, 959 = 7*137, 4389 = 3*7*11*19, 10150 = 2*5^2*7*29, 13321 = 7*11*173, 54481 = 7*43*181, 61467 = 3*7*2927, 92288 = 2^7*7*103, 330925 = 5^2*7*31*61, 368851 = 7*23*29*79, 446236 = 2^2*7*15937) |
A new record of largest multifactorial primes
220502!2+1 is prime! (digits: 541,239) SFukui 01/2017 [url]http://primes.utm.edu/primes/page.php?id=122753[/url] |
[QUOTE=chroma;454307]A new record of largest multifactorial primes
220502!2+1 is prime! (digits: 541,239) SFukui 01/2017 [url]http://primes.utm.edu/primes/page.php?id=122753[/url][/QUOTE] Nice. |
FYI, I updated the first post to redirect to Marian's page.
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