use strict;
use warnings;

chomp( my @unsorted = <DATA> );

my @sorted = map unpack( 'x4a*', $_ ), sort map pack( 'Na*', /(\d+)\D*\z/, $_ ), @unsorted;

print map "$_\n", @sorted;

__DATA__
sequence3.gb.txt
sequence1.gb.txt
sequence7.gb.txt
sequence5.gb.txt
sequence2.gb.txt
sequence4.gb.txt
sequence10.gb.txt
sequence9.gb.txt
sequence8.gb.txt