#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;

my $sample = "041424344454647484940414";
$sample =~ /([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])/; # 24 times the same pattern
print "$1$3$5$7$9$11$13$15$17$19$21$23\n";

my $new = "041424344454647484940414";
$new =~ /(\d).?/g;
print "$1$3$5$7$9$11$13$15$17$19$21$23\n";

my @array = $new =~ /(\d).?/g;
print Dumper \@array;

__END__
$ perl test.pl
012345678901
Use of uninitialized value $3 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $5 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $7 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $9 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $11 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $13 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $15 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $17 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $19 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $21 in concatenation (.) or string at test.pl line 12.
Use of uninitialized value $23 in concatenation (.) or string at test.pl line 12.
0
$VAR1 = [
          '1',
          '2',
          '3',
          '4',
          '5',
          '6',
          '7',
          '8',
          '9',
          '0',
          '1'
        ];