21249Re: [PrimeNumbers] Re: Consecutive occurrences of decadal prime triplets
- Jan 2, 2010rupert.wood wrote:
> Just to avoid unnecessary effort and extra computer time,I used my own unpublished prime pattern finder. It is modified for
> are there any coding shortcuts for this kind of searching?
> Even in the 4-triplet case there would be quite a bit of
> tedious checking to do in each iteration (just asking in
> case someone has developed some generic sort of prime
> pattern searching routine).
each search and not suited for sharing. It could probably easily
find thousands of 4-triplet cases if it was modified for the purpose.
There are many possible shortcuts evolving around avoiding or quickly
eliminating cases where at least one number has a small prime factor.
I searched each of the 194 admissible 5-triplet patterns one at a time,
so in each case there were 15 numbers that had to be prime. Searching
some patterns with few differences at the same time might be more
efficient but I didn't have suitable code for that.
A shortcut you may already use is to only make prp (probable prime)
tests at first, and only make primality proofs later when there is a
complete prp solution.
Using fast tools like C instead of PARI/GP can also speed up many things.
Robin Garcia wrote:
> Does it not matter that primes exist between them?I listed this and the primes for the other cases in my first post
> For instance 9100524636850+n is also prime for n=21
The original post said prime quadruplets are permitted and also listed:
> There is an instance of 4 consecutive triplets at5431, 5437 and 5483 are also prime.
> 5413 5417 5419; 5441 5443 5449; 5471 5477 5479; 5501 5503 5507.
Jens Kruse Andersen
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