Re: primepi bug

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Thu, Jan 26, 2012 at 07:21:23PM -0800, John W. Nicholson wrote:
> ? primepi(nextprime(4000000453))
> %25 = 189961830
> ? primepi(nextprime(4000000454))
>   ***   at top-level: primepi(nextprime(40
>   ***                 ^--------------------
>   *** primepi: bug in PARI/GP (Segmentation Fault), please report
>   ***   Break loop: type 'break' to go back to GP
> break> break

This is a bug which is already fixed in the development branch.
(LGr12- off-by-1 error in primepi() when argument is = primelimit)
However you will just get a different error:
  *** primepi: not enough precomputed primes, need primelimit ~ 4000000483.

The fast sieve-based primepi algorithm is not implemented.

Cheers,
Bill.