Where does these magic numbers come from

Hi, sorry for so many questions.

Where does these magic numbers come from?

```
const JITTER_PATTERN = [
Vector.new(-1 / 12.0, -5 / 12.0),
Vector.new( 1 / 12.0, 1 / 12.0),
Vector.new( 3 / 12.0, -1 / 12.0),
Vector.new( 5 / 12.0, 5 / 12.0),
Vector.new( 7 / 12.0, -3 / 12.0),
Vector.new( 9 / 12.0, 3 / 12.0),
]
```

In your post, you mentioned this:
`We can easily get four samples per pixel by rendering the same set of triangles four times, each time with a slightly different offset and using a color with a different channel each time.`

`slightly different offset` refer to these magic number above? If yes, how can I create this numbers?