There are piles of steel pipes on the construction site, the uppermost layer has 6 steel pipes, and the adjacent lower layer has 2 more steel pipes than the upper layer. There are 6 layers of steel pipes. How many steel pipes are there in total?
工地上有堆钢管，最上层有6根，相邻的下层根数比上层根数多2根．钢管共6层．这堆钢管共多少根．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">2 * 5</gadget>
<output>10</output>

<gadget id="calculator">6 + 10</gadget>
<output>16</output>

<gadget id="calculator">6 + 16</gadget>
<output>22</output>

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

<gadget id="calculator">22 * 3</gadget>
<output>66</output>

<result>66</result>