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 Showing results 1 to 25 of 299 Search took 0.06 seconds. Search: Posts Made By: carpetpool
 Forum: Wagstaff PRP Search 2020-07-26, 13:08 Replies: 0 Views: 96 Posted By carpetpool Wagstaff factors Wagstaff factors currently aren't on the Top20's page and was thinking about asking Prof. Caldwell or one of his editors to consider making an archivable form (https://primes.utm.edu/top20/home.php)...
 Forum: Lounge 2020-07-17, 17:05 Replies: 56 Views: 4,213 Posted By carpetpool Not 25 yet, nor have I been involved in romantic... Not 25 yet, nor have I been involved in romantic relationships just yet. Being a mostly math/computer science/tech forum (myself included), I figured I might ask to those of you who have: How...
 Forum: Riesel Prime Search 2020-07-13, 22:48 Replies: 212 Views: 23,908 Posted By carpetpool Another lucky hit: 26*3^1700041+1 may be... Another lucky hit: 26*3^1700041+1 may be prime, but N divides 3^((N-1)/3))-1, restarting with a=5 Time : 938.494 sec. 26*3^1700041+1 is prime! (811128 decimal digits) Time : 946.942 sec.
 Forum: sweety439 2020-07-12, 18:55 Replies: 934 Views: 27,902 Posted By carpetpool That is incorrect. What if we only know 12.5% of... That is incorrect. What if we only know 12.5% of the factorization of n^2-1 (CHG proof), and thus, niether n+1, nor n-1 has to be trivially written as a product ? What if the factors found were...
 Forum: Riesel Prime Search 2020-07-12, 05:22 Replies: 1,949 Views: 167,114 Posted By carpetpool 273*2^2024810-1 is prime! (609531 decimal digits)... 273*2^2024810-1 is prime! (609531 decimal digits) Time : 1198.071 sec.
 Forum: Miscellaneous Math 2020-07-08, 19:21 Replies: 14 Views: 366 Posted By carpetpool Cunningham Chain of the second kind... Cunningham Chain of the second kind (https://primes.utm.edu/glossary/page.php?sort=CunninghamChain) OP is mentioning a special case of this (k=2, Fermat Primes), there are only finitely such...
 Forum: Riesel Prime Search 2020-07-06, 03:34 Replies: 212 Views: 23,908 Posted By carpetpool This has been my lucky weekend (just yesterday, I... This has been my lucky weekend (just yesterday, I found a T5K prime for CRUS): 26*3^1435875+1 may be prime, but N divides 3^((N-1)/3))-1, restarting with a=5 Time : 1308.400 sec. 26*3^1435875+1...
 Forum: Conjectures 'R Us 2020-07-04, 20:46 Replies: 853 Sticky: Report top-5000 primes here Views: 62,846 Posted By carpetpool R187 has 4 k's to go now: 2868*187^212559-1... R187 has 4 k's to go now: 2868*187^212559-1 is prime! (482904 decimal digits, P = 3) Time : 5885.318 sec.
 Forum: sweety439 2020-07-03, 17:22 Replies: 20 Views: 2,017 Posted By carpetpool I also did a test with PFGW to verify weather... I also did a test with PFGW to verify weather this number was a 3-PRP, or even 3-SPRP or not: >pfgw64 -q"29*32^1745576-1" PFGW Version 4.0.0.64BIT.20190528.Win_Dev [GWNUM 29.8] ...
 2020-06-30, 19:28 Replies: 9 Views: 566 Posted By carpetpool There appear to be two types of Higher order... There appear to be two types of Higher order Carmichael numbers of order m: n such that p^m-1 | n^m-1 for each prime p | n n such that Phi(d,p) | Phi(d,n) for each prime p | n and each divisor...
 Forum: Miscellaneous Math 2020-06-28, 18:28 Replies: 9 Views: 751 Posted By carpetpool A quick improvement to the test: For n = 3... A quick improvement to the test: For n = 3 mod 4, we have: 1) Find b = t^2 + 1 such that Jacobi(b, n)==1 2) gcd(t^3 - t, n)==1 3) Compute u*x + v = (x + t)^((n + 1)/2) mod (n, x^2 + 1) 4)...
 Forum: Information & Answers 2020-06-22, 05:52 Replies: 18 Views: 834 Posted By carpetpool Apart from what others have said, there's nothing... Apart from what others have said, there's nothing stopping you from creating your own algorithm, especially for multiplication. You will want to look at running times of existing algorithms such as...
 Forum: Riesel Prime Search 2020-06-17, 00:56 Replies: 362 Views: 34,157 Posted By carpetpool True. Or until the rate at which candidates are... True. Or until the rate at which candidates are being removed is less than a single LLR test.
 Forum: Twin Prime Search 2020-06-15, 21:51 Replies: 258 Views: 28,841 Posted By carpetpool Here is the complete set: Bases <= 24 checked to... Here is the complete set: Bases <= 24 checked to n=5K, others < 100 checked to n=2K. Also verified smaller twin primes, which I had forgot most of them in my previous list.
 Forum: Proth Prime Search 2020-06-12, 05:34 Replies: 5 Views: 720 Posted By carpetpool I think you are referring to Gaussian Mersenne... I think you are referring to Gaussian Mersenne norms (https://primes.utm.edu/top20/page.php?id=41).
 Forum: Twin Prime Search 2020-06-11, 20:13 Replies: 258 Views: 28,841 Posted By carpetpool I don't suppose newpgen + pfgw would be faster... I don't suppose newpgen + pfgw would be faster than twinsieve ? Here are the twin primes bases up to 48: k*b^n+-1 with k <= n base = 3 (check to n=15000) 2*3^2+1 8*3^10+1
 Forum: Twin Prime Search 2020-06-09, 22:09 Replies: 258 Views: 28,841 Posted By carpetpool k*b^n+-1 with k < n? Also another interesting problem if anyone's interested: Twin primes of the form k*b^n+-1 with k < n --> Due to the limited choices of fixing only base b, there are extremely rare. I tested...
 Forum: sweety439 2020-06-08, 23:23 Replies: 934 Views: 27,902 Posted By carpetpool You could try a simple GP script to eliminate... You could try a simple GP script to eliminate most k's: For instance, (k*3^n+1)/2, we have the following k's remaining at n=3000: h=[]; for(i=1,3000, for(t=1,#g, if(ispseudoprime(...
 Forum: sweety439 2020-06-08, 03:10 Replies: 934 Views: 27,902 Posted By carpetpool (k*b^n+c)/gcd(k+c, b-1) is not a polynomial... (k*b^n+c)/gcd(k+c, b-1) is not a polynomial sequence so it isn't at all related to the Bunyakovsky conjecture. Steps 1 and 2 are trivial enough, but steps 3 and 4 are what make the difference. Step 4...
 2020-06-03, 18:00 Replies: 45 Views: 6,149 Posted By carpetpool p = 1 mod 4 increases the odds of such a prime,... p = 1 mod 4 increases the odds of such a prime, as N = 6*p^n+1 is congruent 7 mod 8, but there is still 1/3 chance --- which at 965K digits, I'm not sure if anyone would be willing to test if N |...
 2020-05-30, 19:44 Replies: 45 Views: 6,149 Posted By carpetpool There is also this (https://oeis.org/A332763)... There is also this (https://oeis.org/A332763) possible sequence I am approaching the T5K range for. It would be interesting to find a prime (k=6) making the "Divides Phi" achievable class...
 2020-05-18, 17:10 Replies: 22 Views: 926 Posted By carpetpool How did you sieve them though? I figured you... How did you sieve them though? I figured you could use the -w option BTW.
 2020-05-17, 19:26 Replies: 22 Views: 926 Posted By carpetpool Srsieve is for numbers of the form k*b^n+-c and... Srsieve is for numbers of the form k*b^n+-c and sr2sieve requires that k=1 or c=1. Thus, you would have to find a program that sieves your requested forms, or use the -f switch in pfgw instead of a...
 2020-05-17, 06:55 Replies: 22 Views: 926 Posted By carpetpool I don't know of any utility that does this but... I don't know of any utility that does this but srfile: >>> srfile --help srfile 0.6.17 -- A file utility for srsieve. Usage: srfile [OPTION ...] -o --output FILE Write...
 Forum: Miscellaneous Math 2020-05-15, 18:39 Replies: 16 Views: 595 Posted By carpetpool You seem to have the right idea. You want to... You seem to have the right idea. You want to calculate 2^n for some integer n. However, this integer n is the one you want to test for primality, and not even 2^n, but 2^n mod n. (n may have,...
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