#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11136191
use warnings;

for my $n (0, 2, 20, 200, 2000, 20000, 200000)
  {
  my @bytes = reverse sprintf('%016X', $n) =~ s/^(?:00)*\B//r =~ /../g;
  print "$n => @bytes\n";
  }