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## #1 Re: This is Cool » Could be new prime Numbers using repdigits » 2016-11-23 17:52:35

Sorry I must have missed one digit while copying the result, it should be:

p=35
Ps=77777777777777777777777777777777813

## #2 Re: This is Cool » Could be new prime Numbers using repdigits » 2016-11-23 01:16:52

Stangerzv wrote:

p should be a prime whereas p=35=5x7, p=51=3x17, p=341=11x31

Okay that's your choice but the results Ps are prime.
BTW: there are no other results up to 16733 (including non primes).

## #3 Re: This is Cool » Could be new prime Numbers using repdigits » 2016-11-21 01:20:13

Stangerzv wrote:

Let d=7

p=5

Ps=77783 [only prime so far for p[n<2000]]

There are more results:

p=35
Ps=7777777777777777777777777777777781

p=51
Ps=777777777777777777777777777777777777777777777777829

p=341
Ps=77777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777778119

## #5 Re: This is Cool » Using Fermat's Little Theorem to find primes. » 2016-05-03 02:49:35

That won't solve the problem of the pseudoprimes. You can use different bases to eliminate most pseudoprimes but some are pseudo for all bases co-prime to p.
These are called Carmichael Numbers.

## #6 Re: This is Cool » Using Fermat's Little Theorem to find primes. » 2016-05-02 22:07:04

I'm not sure what you mean, can you give an example?

## #7 Re: This is Cool » Using Fermat's Little Theorem to find primes. » 2016-05-02 16:21:35

Using Fermat is very fast however this prime test is not deterministic but probabilistic. There are composite numbers that pass this test called pseudoprimes.

## #9 Re: This is Cool » My New Twin Prime Numbers » 2016-05-02 05:58:03

First results for Pt=23: (no perfect twins)
-4475 : 5889137212050938735368472902508869483835853899657458332272001992354134048771473543186122962291841184947527129
+4475 : 5889137212050938735368472902508869483835853899657458332272001992354134048771473543186122962291841184947536079
-11737- : 763535938306412512047674015563031733445522730069155715016873757788272794603779526321867531591867496118778511572255374563
+11737+ : 763535938306412512047674015563031733445522730069155715016873757788272794603779526321867531591867496118778511572255398037
-11848 : 977088126028151808796565733124095583631954744365488527199737265166828731869558855032529267557676836542668809798898003537
+11848 : 977088126028151808796565733124095583631954744365488527199737265166828731869558855032529267557676836542668809798898027233

## #10 Re: Coder's Corner » Linux question » 2016-04-24 21:49:37

With Windows your computer tells you what to do, with Linux your computer does what you want

## #12 Re: This is Cool » A New Way Of Finding If "p" Is Composite. » 2016-04-23 03:22:21

Every composite number is the difference of two squares, a prime is never:

## #13 Re: This is Cool » Twin Prime Proof » 2016-04-23 00:13:10

Cool very
The product of all prime numbers up to a certain prime is called a Primorial

Sometimes the algorithm also works when the result is larger than the next prime squared.

For example:

, p=23, r=22, m=1
and

are both prime but much larger than 23 squared (529).

I am not sure this proves that there is an infinite number of twin primes. The algorithm often finds the same twin primes between 1 and the next largest prime squared. I think you still have to proof that a greater primorial also results in larger twin primes.