#!/usr/bin/env perl use strict; use warnings; sub factorial{ my $n = shift; if($n == 0){return 1;} else{return $n * factorial($n-1);} } sub left_factorial{ my $n = shift; my $sum = 0; for(my $i = 0; $i < $n; $i++){ $sum += factorial($i); } return $sum; } foreach(1..10){ print left_factorial($_), " "; }