User blog:Nayuta Ito/Brainfuck challenge

Brainfuck specification: There are only 9 characters acceptable in Brainfuck. Anything else is ignored. Start with both-side infinitely long array and a pointer. (Imagine a tape and turing machine, but each cell can hold as big numbers as you want) + means to increase the value of cell the pointer is pointing. - means to decrease the value of cell the pointer is pointing. > means to move the pointer to the right. < means to move the pointer to the left. [ means where to go back from ]. ] means to go back to corresponding [ unless the pointer is pointing a zero. (I mean, not a[0], but a[n]==0) . means to display the number at which the pointer is pointing, and then halt. , means to get a number from standard input. Same as scanf in C language. (note: I slightly changed the definitions of ".")
 * 1) means nothing, just make it easy for read (I put them between "sections," or "enters" in C).

I define BF(x) as the biggest displayed number possible with x characters of Brainfuck program. Of course this is uncomputable.

First programs are simple:

BF(1)=0. BF(2)=1 +. BF(3)=2 ++. BF(4)=3 +++. BF(5)=4 ++++.

I think it will go multiplication at around 30 and exponentiation at around 60. Maybe BF(100)>G, but I'm not sure.