return [[ 0, 0, 0, 0 ],
[ 0, 1, 0, -2 ],
[ 0, 2, 0, -4 ],
[ 0, 3, 0, -6 ],
[ 0, 4, 0, 0 ],
[ 0, 5, 0, -2 ],
[ 0, 6, 0, -4 ],
[ 0, 7, 0, -6 ]];;