7
1
2 3
3 4 5
4 5 6 7
5 6 7 8 9
6 7 8 9 10 11
7 8 9 10 11 12 13

//////////////////////////////

int lineNum;
cin >> lineNum;
for (int i= 1; i < lineNum+1; i++){
    for(int __________________)
        cout << j << " ";
    cout << endl;
}