A meeting of 6 members of an executive committee is held. So these 6 members called their 6 subordinates, and each subordinate called their 6 subordinates again. If everyone is notified only once, how many people know that there is a meeting.
一个执委会的6名成员要召开一次会议．于是这6名成员给各自的6个下属打电话，每个下属又给各自的6个下属再打电话．若每个人都只被通知了一次，有多少人知道要开会．
<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<gadget id="calculator">36 + 6 + 1</gadget>
<output>43</output>

<gadget id="calculator">43 * 6</gadget>
<output>258</output>

<result>258</result>