#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using mint = atcoder::modint998244353;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T;
    cin >> T;
    mint div = mint(1) / 2;
    while(T--){
        long long n, m;
        cin >> n >> m;
        vector dp(m, vector<mint>(3));
        dp[0][0] = 1;
        dp[0][1] = n;
        if(n >= 4) dp[0][2] = n * (n - 3) / 2;
        for(int i = 0; i + 1 < m; i++){
            for(int j = 0; j < 3; j++){
                dp[i + 1][0] += dp[i][j];
                dp[i + 1][1] += (n - j) * dp[i][j];
                if(n >= 4) dp[i + 1][2] += ((n - j) * (n - j - 1) / 2 - (n - 2 * j)) * dp[i][j];
            }
        }
        cout << (dp[m - 1][0] + dp[m - 1][1] + dp[m - 1][2]).val() << '\n';
    }
}