my @line_nums = (44, 87, 345);

my $line_num = shift(@line_nums);
my $more = 2;

while (<>) {
   next if $. != $line_num;

   print;

   if ($more) {
      --$more;
      ++$line_num;
      shift(@line_nums) if @line_nums && $line_nums[0] == $line_num;
      next;
   }

   last unless @line_nums;
   $line_num = shift(@line_nums);
   $more = 2;
}