$$
f(a)=f(b)
$$

okay

$$
a^2 - b^2 = (a+b)(a-b)
$$

... et(t) = lfloor 23 * (3 * root(3)(t) + 0.7 * log(t + 5) + 13 + (t mod 86400) / 86400 + 11 * log_2(t) + 17 * sin(2 * pi * t / 86400) + 2 * cos(2 * pi * t / 86400) + lfloor t / 86400 rfloor ^ 2) rfloor mod 4 ...