0, 1, 3, 8, 21, 55, ... According to the law of the above numbers, what is the number after 55?
0，1，3，8，21，55，…按以上数的规律，55后面的数是多少．
<gadget id="calculator">1 - 0</gadget>
<output>1</output>

<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">2 + 6</gadget>
<output>8</output>

<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">5 + 16</gadget>
<output>21</output>

<gadget id="calculator">21 - 8</gadget>
<output>13</output>

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<gadget id="calculator">13 + 42</gadget>
<output>55</output>

<gadget id="calculator">55 - 21</gadget>
<output>34</output>

<gadget id="calculator">55 * 2</gadget>
<output>110</output>

<gadget id="calculator">34 + 110</gadget>
<output>144</output>

<result>144</result>