# [Factor] + `math.unicode`, 23 bytes
```lang-factor
[ 1 - 3 >base "10"⊂ ]
```
[Try it online!][TIO-l1pr3rre]

[Factor]: https://factorcode.org/
[TIO-l1pr3rre]: https://tio.run/##S0tMLskv@h8a7OnnbqWQnVqUl5qjkJtYkgEm9AoSi4pTiyDs0rzM5PyUVIWCotSSksqCosy8EgVrLi7T/9EKhgq6CsYKdkmJxakKSoYGSo@6mhRi/ycn5uQo6P0HAA "Factor – Try It Online"

Based on @allxy's Vyxal/Jelly [answers][1]. Subtract 1 from the input, convert it to base 3, but instead of checking whether each digit is less than two, check whether the result is a subset of `"10"` since that's shorter in Factor.

  [1]: https://codegolf.stackexchange.com/a/246026/97916