mod = 998244353

def solve():
    n,m = map(int,input().split())

    dp = [1,0,0]

    for i in range(m):

        ndp = [0]*3

        for bi in range(3):

            rest = n-bi
            if rest < 0:
                continue

            ndp[0] += dp[bi]
            ndp[0] %= mod

            if rest == 0:
                continue

            ndp[1] += dp[bi] * rest
            ndp[1] %= mod

            if rest == 1 or n < 4:
                continue

            ndp[2] += (rest*(rest-1)//2 - (n-2*bi)) * dp[bi]
            ndp[2] %= mod

        dp = ndp

    return sum(dp)%mod
t = int(input())
for _ in range(t):
    print(solve())