from functools import cache


def solve():
    N = int(input())
    A = list(map(int, input().split()))

    def f(p, d, delta):
        res = 0
        i = p + delta
        while 0 <= i < N:
            d2 = abs(A[p] - A[i])
            if d2 < d:
                res = max(res, f(i, d2, delta) + 1)

            i += delta

        return res

    res = 0
    for i in range(N):
        res = max(res, f(i, INF, -1) + f(i, INF, 1))

    return res


INF = 1 << 60
T = int(input())
for _ in range(T):
    ans = solve()
    print(ans)