C:\test>p1
Perl> use Math::Pari qw[ prime primes nextprime precprime ];;

Perl> print prime 41561;;
500257

Perl> print prime 41562;;
PARI:   *** not enough precalculated primes at (eval 7) line 1, <STDIN> line 4.

##</code><code>##

Perl> 
print scalar localtime; 
$p = 500257; 
$p = nextprime ++$p for 41562 .. 1000000; 
print scalar localtime; 
print $p;;

Tue Nov 14 04:36:02 2006
Tue Nov 14 04:37:07 2006
15485863

##</code><code>##

Perl> print prime 41562;;
PARI:   *** not enough precalculated primes at (eval 9) line 1, <STDIN> line 6.