The problem is that you are reversing the string a few times. The following will do: (defun base8 (n) (let ((t8 (truncate n 8)) (m8 (mod n 8))) (if (= t8 0) (list m8) (append (base8 t8) (list m8))))) EDIT Here's a solution without append, using a helper function.
On average, a kidney weighs approximately 150 to 160 grams and, together, both kidneys weigh about 0.5 percent of total body weight. Usually, the left kidney is slightly larger than the right. These measurements and weights represent the typical ranges of a healthy, adult human kidney.
The apex (pointed end) points down and to the left. It is 5 inches (12 cm) long, 3.5 inches (8-9 cm) wide and 2.5 inches (6 cm) from front to back, and is roughly the size of your fist. The average weight of a female human heart is 9 ounces and a male's heart is 10.5 ounces. The heart comprises less than 0.5 percent of the total body weight.