#! perl -slw
use strict;
use List::Util qw[ shuffle ];


our $N ||= 20e6;

my @tagStems = shuffle 'AAA' .. 'ZZZ';

my $serial = 0;
while( my $stem = pop @tagStems ) {
    for my $suffix ( shuffle 'AAA' .. 'ZZZ' ) {
        printf "%07d\t%s\n", ++$serial, $stem . $suffix;
        exit if $serial > $N;
    };
}


__END__
C:\test>786833
0000001 HBDKCE
0000002 HBDBWB
0000003 HBDRRX
0000004 HBDUJF
0000005 HBDFRH
0000006 HBDMFO
0000007 HBDAEO
0000008 HBDEYC
0000009 HBDCCZ
0000010 HBDXPK
...
0017572 HBDIWS
0017573 HBDQFL
0017574 HBDHYU
0017575 HBDUUL
0017576 HBDCGM
0017577 ZPSQVM
0017578 ZPSOUH
0017579 ZPSPJV
0017580 ZPSGAS
...