Which paddings values are double compared to the others?

<html>
<head><style>img{padding-top: 20px;padding-right: 40px;padding-bottom: 20px;padding-left: 40px;background-color: green;border:solid 2px;width: 100px;height: 100px;}
</style>
</head>
<body>
    <img src="https://getmimo.com/r/trees.png">
</body>
</html>]]>
The second and fourth valuesThe third valueThe first and second valuesThe second padding

The second and fourth values.