my $combinations2;

# ...

sub create_motif2 {  #creates every possible 6-mer

 my $base2 = join ",", qw/a t c g/;
 my $L2 = 6;
 my $string2 = "{$base2}" x $L2;
 my $combinations2 = glob $string2;

#print join ":", $combinations2;
return join ":", $combinations2;
     }



##</code><code>##

my $combinations2 = create_motif2();</p>

<p>Then pass <c>$combinations2