mersenneforum.org sets of 3 primes
 User Name Remember Me? Password
 Register FAQ Search Today's Posts Mark Forums Read

 2017-10-17, 19:53 #1 MattcAnderson     "Matthew Anderson" Dec 2010 Oregon, USA 312 Posts sets of 3 primes Hi all, See this webpage regarding sets of 3 primes. here All primes greater than 2 are odd. Similarly all primes greater than 3 are not divisible by 3. For what it's worth. Matt
2017-10-17, 22:48   #2
science_man_88

"Forget I exist"
Jul 2009
Dumbassville

26×131 Posts

Quote:
 Originally Posted by MattcAnderson Hi all, See this webpage regarding sets of 3 primes. here All primes greater than 2 are odd. Similarly all primes greater than 3 are not divisible by 3. For what it's worth. Matt
seems to be missing the word consecutive see: http://mathworld.wolfram.com/PrimeConstellation.html

 2017-10-17, 23:16 #3 danaj   "Dana Jacobsen" Feb 2011 Bangkok, TH 90910 Posts MathWorld is, not surprisingly, not quite right. They mean to say consecutive primes, as "consecutive numbers" is obviously wrong. The OEIS Wiki has a better page than Mathworld: https://oeis.org/wiki/Prime_constellations It separates the idea of a cluster from a constellation. Matt's page starts by talking about the standard triplets but then notes we can also find 3-clusters. These are not consecutive primes. Code: # replace ... by your list of a,b,... for p,p+a,p+b,... # perl -Mntheory=:all -E 'say for sieve_prime_cluster(,, ...); # e.g. one of Matt's clusters:' perl -Mntheory=:all -E 'say for sieve_prime_cluster(0,1000,102,246);' # or this random meaningless one: perl -Mntheory=:all -E 'say for sieve_prime_cluster(0,1e6, 102,246,384,512,770,896);' The isprime methods are easy to program in a lot of languages (trivial in Pari/GP for instance). The method in the Perl module finds admissable residues, sieves them, then does final primality tests on the remainders. It's fairly fast for large clusters. It is certainly not unique or the first to do it.
 2017-10-18, 00:24 #4 MattcAnderson     "Matthew Anderson" Dec 2010 Oregon, USA 312 Posts Hi all, Thanks for the good post Dana. I appreciate it. Regards, Matt

 Similar Threads Thread Thread Starter Forum Replies Last Post carpetpool Abstract Algebra & Algebraic Number Theory 1 2017-12-28 12:48 Alfred Msieve 2 2017-04-02 07:01 carpetpool carpetpool 1 2017-02-22 08:37 robert44444uk Computer Science & Computational Number Theory 15 2017-01-04 12:39 mfgoode Miscellaneous Math 2 2006-04-04 00:18

All times are UTC. The time now is 20:42.

Sat Dec 4 20:42:04 UTC 2021 up 134 days, 15:11, 1 user, load averages: 1.38, 1.42, 1.32