This is similar to a shuffle routine I wrote in college. Basically, you swap two elements in the array at random. I used to do this n^2 times, but since you have so many elements, that may not be too effective for you. Instead I took a cue from cciulla's post and perform n swaps. For 170,000 elements, it didn't take too long to run on my end.

my @shuffledList = &shuffle(1..170000);

sub shuffle {
   my @sl = @_;  # soon to be Sorted List
   for my $i ( 1..$#sl ) {
      my $x = int(rand() * $#sl);
      my $y = int(rand() * $#sl);
      ($sl[$x], $sl[$y]) = ($sl[$y], $sl[$x]);
   }
   return @sl;
}
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Hope this helps.