for i in xrange(int(raw_input())):
    n = int(raw_input())
    ar = map(int, raw_input().split())

    deu = False
    if (not abs(ar[0] - ar[1]) < ar[-1] < ar[0] + ar[1]) or (not abs(ar[0] - ar[-1]) < ar[1] < ar[0] + ar[-1]) or  (not abs(ar[-1] - ar[1]) < ar[0] < ar[-1] + ar[1]):
        deu = True
        print 1, 2, n
        
    
    if not deu:
        print -1
