Also, you almost certainly don't need those old C-style for loops. and actually, you don't need those $i variables at all.

$number_of_sequences=12;
$max_length=50;
$min_length=30;

my @set;
foreach (0 .. $number_of_sequences) {
   my $aminoseq = genseq($aminoseq);
   print "$aminoseq\n\n";
   push (@set, $aminoseq);
}

sub genseq {

  my $leg = randomlength();
  my $seq;
  foreach (0 .. $leg) {
    $seq .= randomaminoacid();
  }
  return $seq;
}
[download]

or even

sub genseq {
  my $seq;

  $seq .= randomaminoacid() foreach 0 .. randomlength();

  return $seq;
}
[download]

--
<http://www.dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg