"""
print the series 
0 1 3 6 10 15..........
"""

import sys
sys.setrecursionlimit(10**6)

def handshake(n):
    if(n==1):
        return 0
    return (n-1)+handshake(n-1)

t=int(input())
for i in range(t):
    n=int(input())
    print(handshake(n))