import java.util.Scanner;
public class JavaApplication30 {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        int sum=0;
        int t=input.nextInt();
        for(int i=1;i<=t;i++)
        {
            sum=0;
            int n=input.nextInt();
            for(int j=1;j<n;j++)
            {
                sum=sum+j;
            }
            System.out.println(sum);
        }  
    }
}