Calculation: 3**2+6**2+9**2+...+60**2.
计算：3**2+6**2+9**2+…+60**2．
<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<gadget id="calculator">2 * 20</gadget>
<output>40</output>

<gadget id="calculator">40 + 1</gadget>
<output>41</output>

<gadget id="calculator">41 / 6</gadget>
<output>41/6 = around 6.833333</output>

<gadget id="calculator">9 * 20 * 21 * (41/6)</gadget>
<output>25_830</output>

<result>25_830</result>