import collections 
def solve(lst):
	for i in range(0,len(lst)-2):
		if lst[i+1]-lst[i]!=lst[i+2]-lst[i+1] and (lst[i+1]-lst[i]>1 or lst[i+2]-lst[i+1]>1):
			return str(i+1) + " " + str(i+2) +" " + str(i+3)
	return -1

def sort(key):
	return key[0]
ans=[]
n = int(input())
for i in range(n):
	k=int(input())
	lst= list(map(int,input().split()))
	ans.append(solve(lst))
for i in ans:
	print(i)


# for i in ans:
# 	print(i)
