MOD = 998244353


def solve(n, k):
    ans = 0
    for i in range(1, k + 1):
        ans += pow(i + 1, n, MOD)
        ans %= MOD
    return ans


T = int(input())
assert 1 <= T <= 10**5
ktot = 0

for _ in range(T):
    n, k = map(int, input().split())
    assert 0 <= n <= 10**9
    assert 1 <= k <= 200000
    ktot += k
    print(solve(n, k))

assert ktot <= 200000