1RB---_0LC1RE_0LD1LC_1LE0RG_1RF0RC_1RC1RA_1RD0RB

1RB---_0LC1RE_0LD1LC_1LE0RG_1RF0RC_1RC1RA_1RD0RB (bbch) is a non-halting BB(7) TM with an infinite tetrational rule.

Analysis by Shawn Ligocki

11 01^n D> 00   -->  01^n+2 D>
0^4 01^2n D> 0^3  -->  111 01 0001^n 01 D>
0 01^2n+1 D> 0^4  -->  1 11^2n+2 01 D>
1000101 D> 0^5  -->  0100^2 11 01 D>
00010 01^2n D> 0^4  -->  111 01 0001^n-1 0 1^5 01 D>

0001 0101^n D> $  -->  0101^2n+6 D> $

0001^2 0 0101^n D> $  -->  0 0101^{9 2^n - 1} D> $
$ 111 01 0001 0 0101^n D> $  -->  $ 111 01 0001^{9 2^n+1 + 1} 0 0101^38 D> $

Notice that the last two rules mean that any config 0^inf 111 01 0001^2b+1 0 0101^a D> 0^inf will return to a config of that form. And in fact it enters a config like that at step 6490: 0^inf 111 01 0001^1 0 0101^29 D> 0^inf