[seqfan] Re: prime(183963743666669)=?

[Charles Greathouse]

The nth prime tool is great in its range. Outside of that you need to
invert a fast pi(x) finder. I know Dana Jacobsen has an LMO implementation
in Math::Prime::Util. Basic idea: find an x such that li(x) is about n,
then find pi(x) with a fast algorithm, then sieve in blocks until you make
up the difference between pi(x) and n.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Mon, Mar 28, 2016 at 11:10 AM, Zak Seidov <zakseidov at mail.ru> wrote:

>
> Just for fun:
> Version of primeth recurrence (A007097),
> a(n+1) = a(n)-th prime
> where all terms == 1 mod 4:
> 9433,98221,1274353,20062729,374823133,8160590069,
> 203995622429,5782824422729,183963743666669
> Next term, prime(183963743666669)=6508989711850159 (thanks, Hans!)
> is unfortunately  3 mod 4 :(
> Hence this particular sequence is finite full with 9 terms.
> Are there longer versions (with other initial terms / other modules)?
> Thx, Zak
>
>
> >Понедельник, 28 марта 2016, 16:50 +03:00 от Hans Havermann <
> gladhobo at teksavvy.com>:
> >
> >> Can/wish  anyone find this prime?
> >
> >6508989711850159
> >
> >> In general, how to calculate such huge primes with PARI/Mma or what
> else?
> >
> >I used:  https://primes.utm.edu/nthprime/index.php
> >
> >--
> >Seqfan Mailing list -  http://list.seqfan.eu/
>
>
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