mersenneforum.org Sequence of primes formation
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 2016-03-10, 19:41 #1 PawnProver44     "NOT A TROLL" Mar 2016 California C516 Posts Sequence of primes formation I am trying to prove that there are only finitely many of the form k*b^n+c for relatively prime integers k, b, and c. I came across my first example, that there are no primes of the form 34*10^n+3 for n > 0. Is this true. If not, please show me that there are other primes of this form.
 2016-03-10, 20:16 #2 paulunderwood     Sep 2002 Database er0rr 5×701 Posts Code: ? for(n=0,200,if(ispseudoprime(34*10^n+3),print(n))) 0 86 154
 2016-03-11, 00:55 #3 PawnProver44     "NOT A TROLL" Mar 2016 California 3058 Posts So my record failed I take it?
2016-03-11, 00:59   #4
science_man_88

"Forget I exist"
Jul 2009
Dumbassville

203008 Posts

Quote:
 Originally Posted by PawnProver44 So my record failed I take it?
any time k+c is prime n=0 works as a counter to there not being one.

2016-03-11, 04:43   #5
VBCurtis

"Curtis"
Feb 2005
Riverside, CA

11×409 Posts

Quote:
 Originally Posted by PawnProver44 So my record failed I take it?

Also, do you know what "relatively prime" means? If so, why did you provide an example where the numbers are not relatively prime?

Your statement of what you're trying to prove isn't precise enough. Do you mean you are looking for a combination of k,b,c such that there are only finitely many primes of your form? Or are you trying to say that for ANY relatively prime k-b-c there are only finitely many primes?

You should look up what a Riesel number or Sierpinski number are. Or, check the conjectures R us subforum. You'll find examples of k values with *no* primes.

 2016-03-11, 05:56 #6 LaurV Romulan Interpreter     Jun 2011 Thailand 22·2,239 Posts What are you trying to convince him to do??!??!?! He can't be bothered to read srsieve help (30 lines of text), and he has not a freaking idea what a file name is. You want to teach him integrals and programming?
2016-03-11, 06:02   #7
PawnProver44

"NOT A TROLL"
Mar 2016
California

110001012 Posts

Quote:
 Originally Posted by VBCurtis What are you talking about? Also, do you know what "relatively prime" means? If so, why did you provide an example where the numbers are not relatively prime? Your statement of what you're trying to prove isn't precise enough. Do you mean you are looking for a combination of k,b,c such that there are only finitely many primes of your form? Or are you trying to say that for ANY relatively prime k-b-c there are only finitely many primes? You should look up what a Riesel number or Sierpinski number are. Or, check the conjectures R us subforum. You'll find examples of k values with *no* primes.
There are no primes of the form 34*10^n+3 except 37. I was seeing if this would be proved true or false.

2016-03-11, 06:10   #8
LaurV
Romulan Interpreter

Jun 2011
Thailand

22·2,239 Posts

Quote:
 Originally Posted by PawnProver44 There are no primes of the form 34*10^n+3 except 37. I was seeing if this would be proved true or false.
paulunderwood just gave you another two counterexamples.
3400..(another 80 zeroes)..0003 is prime.

 2016-03-11, 06:19 #9 PawnProver44     "NOT A TROLL" Mar 2016 California 197 Posts Awww... come on.... I had tested this form for months and now I just broke the record.
 2016-03-11, 07:41 #11 KobyJane   230D16 Posts Also, Please do not start anymore new threads. With the posts you started, and you could just read carefully what everyone else was saying, you would be able to find several PRPs or primes by now.

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