What property of $n$ does this test?

Question

I have the following sample data:

1       true
3       false
12      false
10      true
7       true
9       false
8       false

My question is, what property of $n$ does this test?

I have tried several things like prime number, composite number, happy number, etc., but nothing seems to fit the test cases. Can anybody help me?

Answer 1

The property is $$n\equiv 1\ (\mod\ 3\ )$$

Answer 2

There can be many answers to this, even as simple as:

Is $n$ a root of $n^3-18n^2+87n-70$?

or

Does $n$ divide $70$?