MB$18$

$.()2"-,.[2]($n$)$ n $==$ o $1($n$-1)+($n$-1)2($n$)$ n $==$ o $$ i else return $2$xpower$2($n$-1)($e$)$ h $($n$,$ k$),)//$: $$ positive $$ n $$ k$$ k $==1$ n $$ n $==$ k $1($n$-1,-1)+($n$-1,)()-$ h $(5,3)[6]($ii$),.$ n $+1000$n$^2-5+5(?)-$