Fill in the numbers according to the rules: 1020, 2040, □, 4080, □; how much should be filled in the second box
按规律填数：1020、2040、□、4080、□；第二个方框中应填多少
<gadget id="calculator">2_040 + 1_020 + 1_020 + 1_020</gadget>
<output>5_100</output>

<result>5_100</result>