my $id_length   = 12;
my $id_char_set = 16;

my $min_data_length = 5;
my $max_data_length = 50;

my $tiny_alphabet_size   = 26;     # a-z
my $small_alphabet       = 37;     # a-z, 0-9 and \s
my $medium_alphabet_size = 97;     # generic western keyboards
my $big_alphabet_size    = 65536;  # utf8
my $world_alphabet_size  = 100713; # unicode standard 5.1

my $counter = 0;

for my $i($tiny_alphabet_size..$world_alphabet_size){
    for my $j($min_data_length..$max_data_length){
        for my $k($j..$max_data_length){
            my $total_size = geometric_series($i,$j,$k);
            if($total_size <  $id_char_set ** $id_length){
                printf " %-5s %-5s %-5s %-5s %-30s\n",
                      $counter++,$i,$j,$k,$total_size;
            }
        }
    }
}


sub geometric_series {
    my($base,$min,$max) = @_;
    my $x;
    for my $i($min..$max){
        $x += $base ** $i; 
    }
    return $x;
}