# import pypyjit
# pypyjit.set_param("max_unroll_recursion=-1")
from collections import *
from functools import *
from itertools import *
from heapq import *
import sys, math,random,time
# input = sys.stdin.readline

mod = 998244353
def answer():
    N,K = map(int,input().split())
    ans = 0
    for k in range(2,K+2):
        ans = (ans + pow(k,N,mod))%mod
    print(ans)
for _ in range(int(input())):
    answer()