use List::Util qw( shuffle );
my @picks = (shuffle 1..15)[0..4];

##</code><code>##

my @picks;
my %seen;
for (1..5) {                          # Five numbers
   my $pick = int(rand(15000)) + 1;   # in 1..15000.
   redo if $seen{$pick}++;
   push @picks, $pick;
}