MOD = 998244353
def mt(A, B):
    C = [[0] * 3 for _ in range(3)]
    for i in range(3):
        for j in range(3):
            tmp = 0
            for k in range(3):
                tmp += A[i][k] * B[k][j]
                tmp %= MOD
            C[i][j] = tmp
    return C

for _ in range(int(input())):
    N, M = map(int, input().split())
    A = [[1, 1, 1],
         [N, N - 1, N-2],
         [N * (N - 1) // 2 - N if N > 3 else 0,
          (N - 1) * (N - 2) // 2 - N + 2 if N > 3 else 0,
          (N - 2) * (N - 3) // 2 - N + 4 if N > 3 else 0]]
    X = [[1, 0, 0],
         [0, 1, 0],
         [0, 0, 1]]
    for i in range(M):
        X = mt(A,X)
        #print(i,X)
    ans = 0
    for i in range(3):
        ans += X[i][0]
        ans %= MOD
    print(ans)