[sdevlin]

I guess it depends what you mean by “crack”. Given f(1), which I assume is public, you can predict all future outputs.

[imaginenore]

I said without knowing the seed, so f(1) is not public, only f(n) formula is.

[benchaney]

f(1) is the first batch of output.

[IshKebab]

That is not what we mean by "crack". Read the article.