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-   -   low nash base 10 sequence (https://www.mersenneforum.org/showthread.php?t=26249)

 pepi37 2020-11-29 20:52

low nash base 10 sequence

On Kamada page the is huge number of low nash base 10 sequences ( plus or minus side) Even with very small sieve depth I can remove many candidates, but I would like to do sieve to at least 1e14. And then I have problem since sr2sieve cannot do such depth on sequence like this 5539879179*10^n+1.

So does anyone here have some simpler solution except sieving one by one with srsieve and sr1sieve?

Update: for now srsieve2 is also in game (and since it is MT) it is fast solution :)

 sweety439 2020-11-30 08:23

[QUOTE=pepi37;564768]On Kamada page the is huge number of low nash base 10 sequences ( plus or minus side) Even with very small sieve depth I can remove many candidates, but I would like to do sieve to at least 1e14. And then I have problem since sr2sieve cannot do such depth on sequence like this 5539879179*10^n+1.

So does anyone here have some simpler solution except sieving one by one with srsieve and sr1sieve?

Update: for now srsieve2 is also in game (and since it is MT) it is fast solution :)[/QUOTE]

This k is too large (>2^32), thus sr2sieve cannot handle, like that sr2sieve cannot handle the sequence (k*b^n+c)/gcd(k+c,b-1) (k>=1, b>=2, c != 0, gcd(k,c) = 1, gcd(b,c) = 1) such that gcd(k+c,b-1) is even (if gcd(k+c,b-1) is odd, then we still can use sr2sieve to sieve the sequence k*b^n+c for the prime not dividing gcd(k+c,b-1) and remove the n such that there is some prime p dividing gcd(k+c,b-1) which also divides (k*b^n+c)/gcd(k+c,b-1))

 pepi37 2020-11-30 22:40

[QUOTE=sweety439;564807]This k is too large (>2^32), thus sr2sieve cannot handle, like that sr2sieve cannot handle the sequence (k*b^n+c)/gcd(k+c,b-1) (k>=1, b>=2, c != 0, gcd(k,c) = 1, gcd(b,c) = 1) such that gcd(k+c,b-1) is even (if gcd(k+c,b-1) is odd, then we still can use sr2sieve to sieve the sequence k*b^n+c for the prime not dividing gcd(k+c,b-1) and remove the n such that there is some prime p dividing gcd(k+c,b-1) which also divides (k*b^n+c)/gcd(k+c,b-1))[/QUOTE]

Sweety439, with all due respect , I didnot ask clarification of my problem ( since I also know sr2sieve doesnot working) I ask any "elegant" solution for my problem.

 Citrix 2020-12-03 04:52

srsieve can handle multiple base 10 sequences at once.

eg)
srsieve.exe --pfgw --nmin 1 --nmax 10000 --pmin 1 --pmax 10000 --factors "3*10^n+1" "2*10^n-1"

 pepi37 2020-12-03 08:44

[QUOTE=Citrix;565108]srsieve can handle multiple base 10 sequences at once.

eg)
srsieve.exe --pfgw --nmin 1 --nmax 10000 --pmin 1 --pmax 10000 --factors "3*10^n+1" "2*10^n-1"[/QUOTE]
Thanks

At the end srsieve2 was the winner since it can handle multiple bases at time and it is MT.

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