js求阶乘和阶乘之和

      // 求阶乘  例如 5! 
       function factorial(n) {
          return  n<1 ? 1 :  n*factorial(n-1)
       }
       console.log(factorial(4));


       // 阶乘之和
       function getSum(n) {
            let sum = 0
            for(var i =1;i<=n;i++){
                 sum = sum+factorial(i)
            }
           return sum 
       }

       console.log(getSum(5));