Find n-th term of series 1, 3, 6, 10, 15, 21.cpp

#include<iostream>
using namespace std;
int main()
{
    int T,n;
	cin>>T;
	while(T--)
	{
	    cin>>n;
	    cout<<n*(n+1)/2<<endl;
	}
	return 0;
}