use strict;
use warnings;

my %cnt;

# Generate all possibilities:
for my $a1 (0 .. 9) {
    for my $a2 (0 .. 9) {
        for my $a3 (0 .. 9) {
            for my $a4 (0 .. 9) {
                my @c = sort ($a1, $a2, $a3, $a4);
                my $s = toStr(@c);
                $cnt{$s}++;
            }
        }
    }
}

my $ttl = 0;
print <<EOHDR;
  num   pct     ttl ttl pct offsets to print
----- ------- ----- ------- ----------------
EOHDR

for my $k (sort { $cnt{$b} <=> $cnt{$a} } keys %cnt) {
    $ttl += $cnt{$k};
    printf "%5u %6.2f  %5u %6.2f  <%s>\n",
        $cnt{$k}, 100*$cnt{$k}/10000.0,
        $ttl,     100*$ttl/10000.0,
        $k;
}

sub toStr {
    my @c = @_;
    my @rv = ();

    for (my $i=1; $i < @c; $i++) {
        if ($c[$i] != $c[$i-1] && $c[$i] != $c[$i-1]+1) {
            push @rv, $c[$i];
        }
    }
    return join(":",@rv);
}

##</code><code>##

$ perl funky.pl
  num   pct     ttl ttl pct offsets to print
----- ------- ----- ------- ----------------
  840   8.40    840   8.40  <7>
  830   8.30   1670  16.70  <8>
  682   6.82   2352  23.52  <6>
  592   5.92   2944  29.44  <>
  524   5.24   3468  34.68  <5>
  508   5.08   3976  39.76  <9>
  408   4.08   4384  43.84  <5:8>
  396   3.96   4780  47.80  <6:9>
  396   3.96   5176  51.76  <6:8>
  366   3.66   5542  55.42  <4>
  336   3.36   5878  58.78  <7:9>
  312   3.12   6190  61.90  <5:7>