sub addmac {
 my ( $mac, $add ) = @_;
  $mac =~ s/://g;
 my $dec = hex($mac);
  $mac = sprintf("%012x", $dec+$add);

  return join(":", $mac =~ /(..)/g );
}

 my $mac = '00:00:00:00:00:f1';
  foreach ( 1 .. 32 ) {
        $mac = addmac($mac,$_*4);
        print "$mac\n";
  }


##</code><code>##

...
00:00:00:00:01:a5
00:00:00:00:01:cd
00:00:00:00:01:f9
00:00:00:00:02:29
00:00:00:00:02:5d
...
00:00:00:00:03:9d
00:00:00:00:03:e9
00:00:00:00:04:39
00:00:00:00:04:8d