User blog:Wythagoras/My BF programs

Exponentation-like program on a long tape
I found the following program:

+>+>...+>+> ++...++ [-<[++...++<]>>>[>]<]. (n*"+>", m*"+", l*"+")

This has an output of \((l+1)^{n-1}(lm+1)\) for \(n\geq1\).

This gives, in general \(\mathbf[BF}(2n+m+l+15) \geq (l+1)^{n-1} \cdot (lm+1)\).