Find the law and fill in the numbers: 2, 9, 30, 93, how many.
找规律填数：2，9，30，93，多少．
<gadget id="calculator">9 - 2</gadget>
<output>7</output>

<gadget id="calculator">7 * 3 * 3 * 3</gadget>
<output>189</output>

<gadget id="calculator">93 + 189</gadget>
<output>282</output>

<result>282</result>