Getting Quick Python includes exercises eleven

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Getting Quick Python includes exercises

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Getting Quick Python includes exercises

Title: seeking 1 + 2 +3 + ... + N and!!!.

Program analysis:

This is the meaning of factorial, a math symbol means from 1 multiplied by 2 multiplied by 3 multiplied by 4 to take up "!" Before the number.

1! It refers to the factorial of 1, 1! = 1;

2! It refers to the factorial of 2, 2! = 1 × 2 = 2;

3! It refers to the factorial of 3, 3! = 1 × 2 × 3 = 6;

And so on.

Any natural number n is greater than 1 represents the factorial method:! N = 1 × 2 × 3 × ...... × n.

n=1                                          #乘数
sum=1                                       #总和
for i in range(1,9):                         #第几个数字
    while n<=i:
        sum=sum*n                           #累×  
        n=n+1
        print(sum)
        

X=int(input('请输入阶乘数字：'))        
n=1                                          #乘数
s=1  
sum=0                                     #总和
for i in range(1,X+1):                         #第几个数字
    while n<=i:
        s=s*n                           #累×  
        n=n+1        
        sum=sum+s
print(sum)