1RB0LD 1RC0RF 1LC1LA 0LE1RZ 1LF0RB 0RC0RE

1RB0LD_1RC0RF_1LC1LA_0LE1RZ_1LF0RB_0RC0RE (bbch) is a former BB(6) champion. It was discovered by Pavel Kropitz on 30 May 2022. This TM runs for over 10↑↑15 steps. See analysis: .

It simulates the following Collatz-like rules, starting at $C(5)$, on tape configurations $C(n)=0^{\mathrm{\infty }}10^{n}110^5\text{<mrow data-mjx-texclass="ORD">C<mo>></mo></mrow>}{0}^{\mathrm{\infty }}$:

$$\begin{array}{lll}C(4k)& \to & Halt(\frac{3^{k+3}-11}{2})\\ C(4k+1)& \to & C(\frac{3^{k+3}-11}{2})\\ C(4k+2)& \to & C(\frac{3^{k+3}-11}{2})\\ C(4k+3)& \to & C(\frac{3^{k+3}+1}{2})\\ \end{array}$$