use strict;

my $ref = symetrical(100);
for my $key (sort {$a <=> $b} keys %$ref) {
   printf "%-10d%d\n",$key,$ref->{$key};
}

sub symetrical {
    my %symet;
    my $max = shift;
    for my $i (0..$max) {
        my $square = $i * $i;
        if (sym($square)) {
            $symet{$i} = $square if sym($i);
        }            
    }
    sub sym {
       $num = shift;
       ($num eq reverse $num) ? $num : '';
    }
    return \%symet;
}


__END__

Sample output

1         1
2         4
3         9
11        121
22        484
101       10201
111       12321
121       14641
202       40804
212       44944