When Xiao Ming was doing the sum of consecutive natural numbers 1, 2, 3, 4, 5, ..., he added one more number, and the result was 149. So what is the added number?
小明在做连续自然数1、2、3、4、5、…求和时，把其中一个数多加了一次，结果和为149，那么多加的这个数是多少
<gadget id="calculator">16 * 17</gadget>
<output>272</output>

<gadget id="calculator">272 / 2</gadget>
<output>136</output>

<gadget id="calculator">149 - 136</gadget>
<output>13</output>

<result>13</result>