In a group of numbers arranged according to the law of 1, 4, 7, 10, 13..., what is the 43rd number?
在按1、4、7、10、13…的规律排列的一组数中，第43个数字是多少．
<gadget id="calculator">43 - 1</gadget>
<output>42</output>

<gadget id="calculator">42 * 3</gadget>
<output>126</output>

<gadget id="calculator">1 + 126</gadget>
<output>127</output>

<result>127</result>