题解 | #牛牛学数列4#
牛牛学数列4
http://www.nowcoder.com/practice/586b114f52034688879342ba45779081
#2022/5/23 21:24
#1 1
#2 1+(1+2)
#3 1+(1+2)+(1+2+3)
#4 1+(1+2)+(1+2+3)+(1+2+3+4)
#n n+1
n=int(input())
sum1,sum2=0,0
for i in range(1,n+1):
sum1+=i
sum2+=sum1
print(sum2)
#1 1
#2 1+(1+2)
#3 1+(1+2)+(1+2+3)
#4 1+(1+2)+(1+2+3)+(1+2+3+4)
#n n+1
n=int(input())
sum1,sum2=0,0
for i in range(1,n+1):
sum1+=i
sum2+=sum1
print(sum2)
