1RB2RA1RA2RB_2LB3LA0RB0RA

1RB2RA1RA2RB_2LB3LA0RB0RA (bbch) is the current BLB(2,4) champion blanking the tape after 1,367,361,263,049 steps

Analysis

A(x,y,z) = 1^x 0 1^y B< 2^z

A(x,2y,z) -> A(0,x,5y+z+1) if x>0
A(0,2y,z) -> blank
A(x,2y+1,z) -> A(x+1,5y+z+1,1)

A(1,0,0) -> A(0,1,1) -> A(1,2,1) -> A(0,1,7) -> A(1,8,1) -> A(0,1,22) -> A(1,23,1) -> A(2,57,1) -> A(3,142,1) -> A(0,3,357) -> A(1,363,1) -> A(2,907,1) -> A(3,2267,1) -> A(4,5667,1) -> A(5,14167,1) -> A(6,35417,1) -> A(7,88542,1) -> A(0,7,221357) -> A(1,221373,1) -> A(2,553432,1) -> A(0,2,1383532) -> blank