I recently played around with wolframalpha, and I found a very interesting property.
This function: $$f(x)=\sin(\cos(x-1)!)$$
yields a negative output for most prime numbers when only integer inputs are graphed. The beginning of the function (close to $y$-axis) is very interesting. For $x=3, x=7, x=11, x=13, x=17, x=23, x=29, x=31, x=47$ which are all primes, the output is negative.
Of course, later on there are less prime inputs that give a negative output, but still prime number inputs dominate the function's negative output values.
Why does this happen, can this be somehow explained?