$number_of_elements = 3;
for($i = $lower_bound ; $i <= $upper_bound-$number_of_elements+1 ; $i++) {
	for ($j = $i + 1 ; $j <= $upper_bound-$number_of_elements+2 ; $j++){
		for ($k = $j + 1 ; $k <= $upper_bound-$number_of_elements+3 ; $k++){
#				print $i.",".$j.",".$k,"====",special_sum($i+$j+$k),"\n";
				if (special_sum($i+$j+$k) == $sum_of_digits){
					push @result, $i.",".$j.",".$k;
				}
		}
	}
}