Uncle Wang sold half and half of all his eggs to the first customer, and the remaining half and half to the second customer. In this way, he always sold half and half of the remaining eggs to each customer , after selling to the seventh customer, he has no more eggs. How many eggs does Uncle Wang have?
王大爷把他所有鸡蛋的一半又半个卖给第一个顾客，把余下的一半又半个卖给第二个顾客，就这样，他总把所余鸡蛋的一半又半个卖给各个顾客，卖给第7个顾客以后，他已一个鸡蛋也没有了，王大爷原来有鸡蛋多少个．
<gadget id="calculator">0.5 * 2</gadget>
<output>1</output>

<gadget id="calculator">1 + 0.5</gadget>
<output>1.5</output>

<gadget id="calculator">1.5 * 2</gadget>
<output>3</output>

<gadget id="calculator">3 + 0.5</gadget>
<output>3.5</output>

<gadget id="calculator">3.5 * 2</gadget>
<output>7</output>

<gadget id="calculator">7 + 0.5</gadget>
<output>7.5</output>

<gadget id="calculator">7.5 * 2</gadget>
<output>15</output>

<gadget id="calculator">15 + 0.5</gadget>
<output>15.5</output>

<gadget id="calculator">15.5 * 2</gadget>
<output>31</output>

<gadget id="calculator">31 + 0.5</gadget>
<output>31.5</output>

<gadget id="calculator">31.5 * 2</gadget>
<output>63</output>

<gadget id="calculator">63 + 0.5</gadget>
<output>63.5</output>

<gadget id="calculator">63.5 * 2</gadget>
<output>127</output>

<result>127</result>