wolfram's random generator

Despite its fundamental simplicity, the rule 30 elementary CA is conjectured to generate a purely random sequence along its center column. It reputably excels at many statistical tests of randomness, and Mathematica includes it as a choice of RNG.

For my own conviction, it was enough to find that the expression sum (take 80 $ rands 5000) `div` 80 produces 2525.

Since each random bit requires computing a full cell generation, this algorithm quickly slows down. I assume more pragmatic implementations solve this by perhaps re-seeding the automaton after some number of iterations.