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.
1. Skin. The average weight of skin in human body is about 10,886 grams (~10.1 kg; 384,0 oz) which varies according to the size and weight of human being. It is a major organ of the body, forming about 8% of its total mass and having an area between 1.2 to 2.2 meter square.