74515

Run ID	Author	Problem	Lang	Verdict	Score	Time	Memory	Code Length	Submit Time
74515	邢逸轩	数列求和	C++	Accepted	100	0 MS	256 KB	143	2023-05-27 14:09:01

#include<bits/stdc++.h> using namespace std; int n; unsigned long long ans; int main(){ cin>>n; cout<<n*(n+1)*(n*2+1)/6; return 0; }