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Message boards : AP26 - AP27 Search : What algorithm is used to find AP?

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Message 129746 - Posted: 23 May 2019 | 18:41:34 UTC

My question is: what algorithm is used to find APs?

I'm going to use my big AP but i think is the same at all the others

185164481362593913+121857779*23#*n for n=0..20

I found that 185164481362593913 is prime and 121857779 too, I would like know how the sistem select them.

END383

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123547534^32768+1 (GFN 15) 265154 digits

34945494^16384+1 (GFN 14) 123591 digits

157959668^8192+1 (GFN 13) 67,163 digits

Ravi Fernando
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Message 129748 - Posted: 23 May 2019 | 19:17:17 UTC - in response to Message 129746.

This thread has some general information about the AP search. The algorithm was designed by Jarosław Wróblewski, who gives a summary of it here:
How to search for 26 primes in arithmetic progression?.

JeppeSN

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Message 129768 - Posted: 24 May 2019 | 14:58:36 UTC

It is true that 121857779 is a prime, but that is insignificant.

You have found another AP:

140980475961780677+121745694*23#*n for n=0..20

and 121745694 is not a prime. (It is 2 * 3 * 7^2 * 414101.)

Not sure if this is what you ask, but from the list of your AP finds, if you click on each line, you can see the primes that constitute the progression.

For an AP21, there are 21 primes in the progression, and they are positioned with uniform spacing on a number line.

/JeppeSN

Message boards : AP26 - AP27 Search : What algorithm is used to find AP?