When Xiaogang was doing the sum of consecutive natural numbers 1, 2, 3..., he added one more number, and the result was 149. So what is the added number?
小钢在做连续自然数1，2，3…求和时，把其中一个数多加了一次，结果是149，那么多加了的数是多少？
<gadget id="calculator">16 * 17</gadget>
<output>272</output>

<gadget id="calculator">298 - 272</gadget>
<output>26</output>

<gadget id="calculator">26 / 2</gadget>
<output>13</output>

<result>13</result>