It is known that a△b=a**2+4b, then 1△2△3=how much.
已知a△b=a**2+4b，则1△2△3=多少．
<gadget id="calculator">7 ** 2</gadget>
<output>49</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">49 + 12</gadget>
<output>61</output>

<result>61</result>